Reliable HOB Overflow Guide

[jservedio]

Disclaimer: If you have the option (at all) of getting an internal overflow or a glass-holes style overflow - GO THAT ROUTE!!! It is a far better, far cheaper solution. However, It's been over a year since I've put this HOB on my tank and about 2 months since I converted it to run on FULL SIPHON as a Herbie (with no backup drain). But, I added a SECOND GRI Water Sensor on the tank to shut off the return pump if the tank is going to overflow. Neither the float switch or GRI switch has been tripped in over a year (except for me testing them). These things can definitely be reliable with the right precautions, parts, and maintenance. However, I want to reiterate I am not saying you should go out and get a HOB if there is ANY possible opportunity to do it the right way internally.

 

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I know a lot of people here who either converted their freshwater tank to a reef or simply added a sump to a previously sumpless tank were forced to use a HOB overflow. I have read countless stories of overflowing tanks caused by these and had a close call this past week. Because of this, I decided to put together a guide on exactly what you will need to make the most reliable HOB overflow possible (which ends up being less prone to flood than most people's internal overflows!). HOB Overflows have a reputation of being ticking time bombs - don't let yours explode!

 

Getting the most reliable overflow you possibly can is not going to be cheap - the entire setup for my 20g cost $150. For this, I could have easily bought a new reef-ready tank with internal overflows pre-drilled. If you are reading this and don't have a tank set up yet - BUY A REEF READY TANK WHILE YOU CAN! For me, it was too late. I converted a FW tank to SW and already had it packed with SPS when I wanted to add a sump. I wish someone had a guide like this when I started out.

 

However, If you are forced to go the HOB route keep reading - you aren't doomed to a flood. You can make your HOB overflow 100% fail-safe:

 

1. Start with a Quality HOB Overflow:

If you buy cheap - it will never be reliable. The single most important feature your HOB overflow can have is a pump connection on the siphon tube/channel This allows you to connect a diaphragm pump to start or restart the siphon automatically. This way if the power fails or your water level drops too low, you don't lost your siphon! The pump will restart it when the power comes back on or the water level rises. I would suggest the CPR CS series HOB Overflows. They are solidly made, use a siphon channel instead of tube (making it nearly possible to clog), and most come pre-packaged with a sump to restart your siphon.

Edit: Lifereef is a better design. Spend the money on this.

 

2. Use a Siphon Pump:

The HOB overflow requires a siphon to work. It siphons water from your tank to a lower-level outside of your tank so it can be drained. Doing a water change, you know how easy it is for a siphon to break. If the siphon breaks, that's it - your tank will overflow. Using a vacuum/diaphragm pump (Like the Tom's Aqualifter Pump) that connects to the siphon tube/channel will automatically start or restart the siphon for you. This way if the siphon breaks when the water level drops or the power goes out - it will be restarted as soon as the water comes back up or the power comes back on. This is the SINGLE best thing you add to your HOB overflow.

 

 

3. Add a Float Switch:

This is the final line of defense before a flood and isn't useful for just HOB overflows; this is useful for ALL overflows. Should the siphon on the overflow fail, the overflow itself become blocked/obstructed, or the drain pipe clog - water will be entering your tank but not leaving. This WILL cause a flood: HOB overflow or not. This is where the float switch comes in. By connecting the float switch to your return pump, should the water in the tank rise enough to cause the float switch to trip, the power to your return pump will be cut off. AutoTopoff.com makes GREAT systems for this and they are very reasonably priced. The "Nano Upper" has a very small float switch, a pre-bent bracket, and a built in 12v relay to keep 110 volts away from your tank. This is also very easy to DIY yourself to save some money.

 

4. Add a Check-Valve:

Now that you have a siphon pump - you have also created a place for air to enter the siphon tube/channel should the pump stop working. Most diaphragm pumps have check valves inside of them - but they are NOT very reliable. If the pump fails, usually they fail because they are clogged. The check valves inside the pump are the smallest channels in the pump so they are where the pump tends to clog. If this happens, you will slowly lose your siphon. To prevent this, simply add an all-plastic airline-check valve between your HOB Overflow and your Siphon Pump. This is the best $1-$2 dollars you can spend! Just this past weekend, my aqualfiter pump was clogged in this exact way and I partially lost siphon. If I wasn't home, my house would have flooded - something that could have been prevented for two dollars or less....

 

5. Add a Pump Pre-Filter:

Since diaphragm pumps contain several tiny passages that are easily clogged with detritus, you should add a pre-filter to the pump. They are simply a small container with an in/out airline barb with a small sponge inside. They are typically $5 or less and you can order them when you get your pump. I simply velcro this pre-filter on top of my HOB overflow so I can always tell when it needs ot be cleaned.

 

 

Here is a picture of the entire setup that I recently finished on my tank:

 

I am using the CPR CS50 overflow ($89.95), a Tom's AquaLifter Diaphragm Pump ($17.99), an AutoTopoff.com "Nano-Upper" float switch w/ a nano bracket and Relay Box ($42), the Aqualifter Pre-Filter, and a generic Airline Check Valve ($1). $150 later, I have peace of mind and have no worry in the world that my tank will overflow. I trust it more than enough to go on vacation and, leaving the country, and not having to worry about coming home to a flooded home or burned down apartment building...

 

 

Additional Precautions for ALL Overflows/Sumps:

• When building your sump, make your return chamber as small as you can make it while still fitting your return pump and ATO. You want your tank to able to handle the entire volume of your return chamber without overflowing if possible.
• Connect your ATO to your float switch in addition to your return pump - don't dump RODI into your tank if your HOB fails.
• Ensure your sump has enough empty space to handle all the water that will drain into the sump when your return pump turns off (power outage, feeding, etc).
• Put a check valve on your return plumbing - you don't want your tank to be siphoned into your sump if your return pump shuts off.

[TheKleinReef]

2. Use a Siphon Pump:

The HOB overflow requires a siphon to work. It siphons water from your tank to a lower-level outside of your tank so it can be drained. Doing a water change, you know how easy it is for a siphon to break. If the siphon breaks, that's it - your tank will overflow. Using a vacuum/diaphragm pump (Like the Tom's Aqualifter Pump) that connects to the siphon tube/channel will automatically start or restart the siphon for you. This way if the siphon breaks when the water level drops or the power goes out - it will be restarted as soon as the water comes back up or the power comes back on. This is the SINGLE best thing you add to your HOB overflow.

 

after 2 of the aqua lifters failed on me i switched to the rio600 pump. and i never looked back.

 

awesome guide though!

[jservedio]

after 2 of the aqua lifters failed on me i switched to the rio600 pump. and i never looked back.

 

awesome guide though!

Were you using a pre-filter on the aquaqlifer? If you weren't - the diaphragm entrance/exit valves probably just clogged. If you are putting tank water into a Tom's Aqualifter, you HAVE to use a pre-filter otherwise it will clog. The valves are approximately 1/8" in diameter and are VERY tiny. The smallest piece of detritus will clog it and make it seem like it is "dead". Unless the epoxy casing on the pump cracked, it wasn't dead. They are nearly indestructible. I bet if you take those pumps apart, you will find the valves clogged.

 

If you clog an aqualifter, a vinegar soak will NOT work to unclog it since the passages are so tiny and they are guarded by flap valves. You have to take htem apart. THe only part on the pump that can break is the actual diaphragm itself and they are less than $2 to replace both of them (and they include the valves).

 

Rio pumps are okay, but they are far more vulnerable to breaking since they use impellers which need to be replaced. That, and most Rio pumps are NOT UL certified.

 

I have 2 aqualifter pumps on my tank right now - one of them has been running for over a year straight without ever turning off - the other one is used by my ATO and has never had problems either.

[dixiedog]

Poppycock. Just drill the damm tank and be done with it.

 

If you're not willing or capable of doing that, or having it done, just go sumpless.

[ExSmoker]

nice guide thanks for posting.

[rklontz]

Good guide and the float switch is a great idea but if you were really concerned with reliability you wouldn't have used a CPR overflow.

 

With a properly constructed hob siphon overflow you will not need to have an aqualifter or some other form of pump to maintain operation or for it to restart in case of a power failure.

[malady]

yeah I would not call a cpr 100% reliable

 

but good thread I might need to try that float switch

to pair up with my mame even tho I have never had a problem

 

I find most of the horror stories are form people not setting up the tubing correctly or not cleaning and maintaining the overflow

[TheKleinReef]

Were you using a pre-filter on the aquaqlifer? If you weren't - the diaphragm entrance/exit valves probably just clogged. If you are putting tank water into a Tom's Aqualifter, you HAVE to use a pre-filter otherwise it will clog. The valves are approximately 1/8" in diameter and are VERY tiny. The smallest piece of detritus will clog it and make it seem like it is "dead". Unless the epoxy casing on the pump cracked, it wasn't dead. They are nearly indestructible. I bet if you take those pumps apart, you will find the valves clogged.

 

If you clog an aqualifter, a vinegar soak will NOT work to unclog it since the passages are so tiny and they are guarded by flap valves. You have to take htem apart. THe only part on the pump that can break is the actual diaphragm itself and they are less than $2 to replace both of them (and they include the valves).

 

Rio pumps are okay, but they are far more vulnerable to breaking since they use impellers which need to be replaced. That, and most Rio pumps are NOT UL certified.

 

I have 2 aqualifter pumps on my tank right now - one of them has been running for over a year straight without ever turning off - the other one is used by my ATO and has never had problems either.

 

it didn't clog, it just stopped working. i'll never use one of them again. i feel as though there are more reliable pumps on the market for overflow boxes. i've heard to many stories where the aqua lifter pumps fail, with or without a prefilter.

[jservedio]

Poppycock. Just drill the damm tank and be done with it.

 

If you're not willing or capable of doing that, or having it done, just go sumpless.

 

Sorry - but a tank full of SPS doesn't really like being drilled and having uncured silicone in it. To put an overflow in my tank, I would have had to basically pull everything out for a week, which isn't exactly possible when half your rocks are attached via SPS colonies.

 

When you have colonies that cost more than the price of a HOB overflow, siphon pump, pre-filter, and float switch - it is a more viable option than risking all of your coral. If you don't have place to take out ALL of your coral for a week, you have no business drilling the tank unless your are going to settle on an external durso with no overflow.

 

Sure, maybe softies and a few very hardy LPS will make it through the curing process for silicone, but nearly every SPS is not going to make it. I don't know about you - but I don't have a place to put all my corals for a week considering I have a 20g tank.

[jservedio]

Good guide and the float switch is a great idea but if you were really concerned with reliability you wouldn't have used a CPR overflow.

 

With a properly constructed hob siphon overflow you will not need to have an aqualifter or some other form of pump to maintain operation or for it to restart in case of a power failure.

What would you consider a more reliable siphon overflow than the CPR? I used a dual-tube siphon overflow on a 55g FW tank years ago at my parents house (temporarily, it didn't normally have a sump) and that thing was 10x worse than the CPR. As far as I've seen, unless you DIY it, the CPR (or others of the same channel design) is the nicest one I have found.

 

Of course the CPR doesn't require a pump to maintain operation if the power goes out, BUT if air gets inside ANY HOB overflow through accumulation of microbubbles, from the DT water level dropping too far, etc, you NEED a pump to draw that air out unless you are there to handle it. If you have a HOB overflow and your return pump stops working, your DT water level will drop and air will enter your siphon. If that pump decides to come back on or clears a clog in the system, the DT water level will rise and your siphon will NOT start again without a pump.

 

The pump isn't required for basic operation, but IMO if you are risking a HOB overflow, it is required as a backup. If you risk your apartment/house to a HOB overflow, you should be doing all you can to mitigate that risk.

 

yeah I would not call a cpr 100% reliable

 

but good thread I might need to try that float switch

to pair up with my mame even tho I have never had a problem

 

I find most of the horror stories are form people not setting up the tubing correctly or not cleaning and maintaining the overflow

I had a very close call just a few weeks ago and I set everything up correctly and maintained it properly. I built my entire sump around the inherent weakness of a HOB overflow. The horror stories are "just everyone else being retarded" until it happens to you

 

Look how clean my overflow is in the picture - obviously I maintain it.

[dixiedog]

Sorry - but a tank full of SPS doesn't really like being drilled and having uncured silicone in it. To put an overflow in my tank, I would have had to basically pull everything out for a week, which isn't exactly possible when half your rocks are attached via SPS colonies.

 

When you have colonies that cost more than the price of a HOB overflow, siphon pump, pre-filter, and float switch - it is a more viable option than risking all of your coral. If you don't have place to take out ALL of your coral for a week, you have no business drilling the tank unless your are going to settle on an external durso with no overflow.

 

Sure, maybe softies and a few very hardy LPS will make it through the curing process for silicone, but nearly every SPS is not going to make it. I don't know about you - but I don't have a place to put all my corals for a week considering I have a 20g tank.

 

Like I said. My sincere advice to anyone in that position is go sumpless. I hate to come off as a jerk, but I'd be a bigger jerk to let some poor clueless noob read this thread and think a HOB overflow is a good, viable option in a reef tank.

 

It's not, it never was, and it never will be.

 

You are giving very bad advice.

[jservedio]

Like I said. My sincere advice to anyone in that position is go sumpless. I hate to come off as a jerk, but I'd be a bigger jerk to let some poor clueless noob read this thread and think a HOB overflow is a good, viable option in a reef tank.

 

It's not, it never was, and it never will be.

 

You are giving very bad advice.

 

Really? It's bad advice to tell people how to make their HOB Overflow more reliable and possibly prevent a fire or flood damage? I stated TWICE at the top of my thread that it is FAR better to buy a reef-ready tank. Sure, sumpless works for some people, but it does NOT work for me and I would never go sumpless in my tank. There are plenty of other people on this forum who use a HOB overflow in order to have a sump - should I not create a write up to tell them how to make their setup more reliable?

 

Some noob reading this (who ACTUALLY reads the post, which you seem to have not done) would see "Oh, it'll be cheaper for me to go out and buy a reef-ready tank because adding a HOB overflow is going to be more expensive than a new tank" How you got out of my thread that I am advocating for people to go out and buy HOB Overflows I do not know...

And someone in a position like mine, where a HOB Overflow IS viable isn't going to be a noob. If they have their rock structure glued together by the skeletons of SPS they aren't a noob and know what they are doing...

 

As long as manufacturers continue to sell HOB Overflows, people are going to use them. If they are going to use them, they should make them more reliable. Simple as that.

 

Beside just simply stating that my setup isn't viable - please tell my why a HOB overflow isn't a viable option provided it is sufficiently backed up and it's weaknesses are addressed? There is no failure point in my setup - period. It simply will NOT cause a flood. The chances of my HOB overflow setup failing are lower than a standard internal overflow with a single drain.

 

Are you an engineer? Have you tested any of this? Have you ever owned any of these products? I have and I have spent many hours testing this in every conceivable way. I have created failures (including multiple system failures) in every single possible point from the overflow to the return and the system has yet to cause a flood.

 

You do come off as a huge jerk - because you assume some noob isn't going to read what I said (twice) about buying a reef ready tank and think this is a good option. That is stupid - by your logic we shouldn't talk about keeping SPS or expert level fish because some noob might think it's easy and end up killing a bunch of coral and fish...

[TheKleinReef]

but I'd be a bigger jerk to let some poor clueless noob read this thread and think a HOB overflow is a good, viable option in a reef tank.

 

It's not, it never was, and it never will be.

 

You are giving very bad advice.

 

its pretty viable... and his advice is making it more reliable.

[1.0reef]

Or just get a lifereef overflow....

[Hart24601]

Great ideas! I have been using a CPR overflow for quite a while now and the system has been working great. I like the switch idea for return pump. I really wish this guide was around when I was setting my system up.

[namxas]

Nice write-up, and good follow-up, altho I have to PERSONALLY disagree with the CPR O/F's...since they're unreliable "out of the box", they should come with a siphon pump.

 

IMHO/IME, the U-tube type of O/F's are much more reliable and don't require a "helper pump".

 

However, as stated, a pumped CPR O/F works fine with the aqualifter...lots of ways to skin the same cat in this hobby, and just as many opinions.

 

Again, good write-up!

[Esage]

Like I said. My sincere advice to anyone in that position is go sumpless. I hate to come off as a jerk, but I'd be a bigger jerk to let some poor clueless noob read this thread and think a HOB overflow is a good, viable option in a reef tank.

 

It's not, it never was, and it never will be.

 

You are giving very bad advice.

 

I used a HOB overflow on a reef tank for over a year, with no problems. HOB overflows work if setup properly.

[GHill762]

My Eshoppes overflow works flawlessly. no bubbles in tube (they pass right through), always restarts, relatively quiet, impossible to clog (I have foam in the tank side to cover the opening). I have not once been concerned about flooding issues.. If drilling isn't an option, Eshoppes will take care of you. Lifereef is also a great overflow, but they are pricey and can be hard to come by (there is a wait). Also, I think Eshoppes is the same design as lifereef from what I can tell..

 

I have never used a pump, although I could see how it would be helpful if you have air bubble issues.. then again, if you're having air bubble issues it means you need a bigger return pump.

[dixiedog]

Really? It's bad advice to tell people how to make their HOB Overflow more reliable and possibly prevent a fire or flood damage? I stated TWICE at the top of my thread that it is FAR better to buy a reef-ready tank. Sure, sumpless works for some people, but it does NOT work for me and I would never go sumpless in my tank. There are plenty of other people on this forum who use a HOB overflow in order to have a sump - should I not create a write up to tell them how to make their setup more reliable?

 

Some noob reading this (who ACTUALLY reads the post, which you seem to have not done) would see "Oh, it'll be cheaper for me to go out and buy a reef-ready tank because adding a HOB overflow is going to be more expensive than a new tank" How you got out of my thread that I am advocating for people to go out and buy HOB Overflows I do not know...

And someone in a position like mine, where a HOB Overflow IS viable isn't going to be a noob. If they have their rock structure glued together by the skeletons of SPS they aren't a noob and know what they are doing...

 

As long as manufacturers continue to sell HOB Overflows, people are going to use them. If they are going to use them, they should make them more reliable. Simple as that.

 

Beside just simply stating that my setup isn't viable - please tell my why a HOB overflow isn't a viable option provided it is sufficiently backed up and it's weaknesses are addressed? There is no failure point in my setup - period. It simply will NOT cause a flood. The chances of my HOB overflow setup failing are lower than a standard internal overflow with a single drain.

 

Are you an engineer? Have you tested any of this? Have you ever owned any of these products? I have and I have spent many hours testing this in every conceivable way. I have created failures (including multiple system failures) in every single possible point from the overflow to the return and the system has yet to cause a flood.

 

You do come off as a huge jerk - because you assume some noob isn't going to read what I said (twice) about buying a reef ready tank and think this is a good option. That is stupid - by your logic we shouldn't talk about keeping SPS or expert level fish because some noob might think it's easy and end up killing a bunch of coral and fish...

 

You're right, I am a jerk. What could possibly go wrong with a $17 Aqualifter and a $1 check valve?

[rklontz]

What would you consider a more reliable siphon overflow than the CPR? I used a dual-tube siphon overflow on a 55g FW tank years ago at my parents house (temporarily, it didn't normally have a sump) and that thing was 10x worse than the CPR. As far as I've seen, unless you DIY it, the CPR (or others of the same channel design) is the nicest one I have found.

 

Of course the CPR doesn't require a pump to maintain operation if the power goes out, BUT if air gets inside ANY HOB overflow through accumulation of microbubbles, from the DT water level dropping too far, etc, you NEED a pump to draw that air out unless you are there to handle it. If you have a HOB overflow and your return pump stops working, your DT water level will drop and air will enter your siphon. If that pump decides to come back on or clears a clog in the system, the DT water level will rise and your siphon will NOT start again without a pump.

 

The pump isn't required for basic operation, but IMO if you are risking a HOB overflow, it is required as a backup. If you risk your apartment/house to a HOB overflow, you should be doing all you can to mitigate that risk.

 

I had a very close call just a few weeks ago and I set everything up correctly and maintained it properly. I built my entire sump around the inherent weakness of a HOB overflow. The horror stories are "just everyone else being retarded" until it happens to you

 

Look how clean my overflow is in the picture - obviously I maintain it.

The only HOB overflows I have ever used are Lifereef's and have never had one loose suction over time or fail to start after a power outage and I live in an area where outages happen far to frequently and for extended periods of time.

 

A CPR overflow will loose suction over time which is why CPR states "you will need to periodically draw out any air that accumulates" and they will not self start after they are primed. If you don't believe me unplug the aqualifter and cap off the suction line for a week or 2 and see what happens. Check out http://www.lifereef.com/siphon.html and you will see the key differences.

 

Sure drilling is the best option but not everyone has the skillset or tools to do so which is why we have HOB overflows. IMO any overflow that requires a mechanical device to maintain suction is not a true suction overflow and a waste of money.

 

The biggest plus of the float switch is in case of an obstruction in the overflow.

[jservedio]

You're right, I am a jerk. What could possibly go wrong with a $17 Aqualifter and a $1 check valve?

 

Which is why there is a float switch - have you not read any of my post? If a pump, check valve, AND float switch go bad all at the EXACT moment that the siphon breaks (which has happened once in a year of operation, and DIDN'T cause a flood - even without all the redundancies in place I have now)...well - you should probably have been struck by lightening a few times by now.

 

Name a failure in my system and I will take a video of me causing that failure so you can watch how it works flawlessly and my tank doesn't overflow...

 

If you want to tell people you personally feel that the setup I describe is unreliable - fine, you are entitled to your opinions. BUT, don't go telling people this is bad advice when you have absolutely nothing to back it up. I've spent a good deal of time testing this and putting it together and I know for a fact it works. Just because you talked yourself out of a sump because you don't have a drilled tank or just because you have an internal overflow doesn't mean every other option isn't viable.

 

I will put my money where my mouth is and prove this thing is 100% reliable - name a what you think is a weakness and I will take it offline and put it on video. If you think the $1 check valve failing or the pump failing will cause my tank to overflow - I will rip the check valve out and unplug the pump and you can watch my tank not overflow (Because I've tested that already...both of them failing at the same time)

[jservedio]

The only HOB overflows I have ever used are Lifereef's and have never had one loose suction over time or fail to start after a power outage and I live in an area where outages happen far to frequently and for extended periods of time.

 

A CPR overflow will loose suction over time which is why CPR states "you will need to periodically draw out any air that accumulates" and they will not self start after they are primed. If you don't believe me unplug the aqualifter and cap off the suction line for a week or 2 and see what happens. Check out http://www.lifereef.com/siphon.html and you will see the key differences.

 

Sure drilling is the best option but not everyone has the skillset or tools to do so which is why we have HOB overflows. IMO any overflow that requires a mechanical device to maintain suction is not a true suction overflow and a waste of money.

 

The biggest plus of the float switch is in case of an obstruction in the overflow.

 

I looked at both the eshopps and the lifereef and they are both great systems. I agree the way they have the siphon set up is much more reliable than the CPR. The only thing I worried about with them is a failure of the return pump causing the DT level to drop below the siphon and causing it to break then having the return pump come back on. This is purely from looking at pictures - so if it doesn't happen, let me know. I went to school for engineering so all I can think about are failure scenarios. I turn off my return pump every single time I feed the tank and don't like restarting the siphon - I was worried about losing siphon when the return pump went off with the other designs.

 

I agree BOTH of those have a better siphon system to prevent siphon break than the CPR, but I feel they are more prone to clogging since they use a tube instead of a wide open channel.

 

They are Pros and Cons to both units and I think the CPR, eshopps, and LifeReef would all work great - provided you addressed any inherent design weaknesses and made sure that

1. You had a float switch to handle complete loss of your drain and

2. Your sump had room to hold all the water that dumps in when you shut off your return pump (but basically EVERY sump has this and most people don't really think about it).

 

All three of them are quality units and would fit my #1 suggestion of "Start with a Quality Overflow". No matter which one you choose, you still definitely want to back it up with a float switch. A HOB Overflow without a float switch is just asking for trouble.

 

Edit: The ONLY reason I mentioned the CPR Overflow as an example is because it is the one I am familiar with and the one I know 100% will work with my suggestions. I didn't mean it to disparage any other quality overflow.

[jservedio]

Or just get a lifereef overflow....

 

The lifereef can still clog and can still lose siphon - this is about accounting for failure scenarios. Something that only happens once in a year (or possibly never if you are lucky). The Lifereef clogs easier than the CPR does - so even with the LifeReef these are all still very good suggestions - ESPECIALLY the float switch. I am not promoting the CPR or LifeReef - they are both great Overflows (the lifereef may even be better!) but that doesn't mean just because you have the lifereef you shouldn;t be backing it up.

 

Anyone who has a HOB Overflow of ANY sort should be backing it up - with check valves should you have a siphon-start port and with a float valve in the event of total drain loss (clog or otherwise).

 

I'll say it again because it is important - If you have a HOB Overflow, the BEST thing you can do is go out and buy a float switch that is connected to your return pump. Not having one is playing fire, you will get burned some day if you keep it up long enough.

[jservedio]

Nice write-up, and good follow-up, altho I have to PERSONALLY disagree with the CPR O/F's...since they're unreliable "out of the box", they should come with a siphon pump.

I couldn't agree more - out of the box they are SUPER dangerous - just asking for a flood. They really shouldn't sell them without some sort of pump. When I bought mine it was packaged with a pump - but I see on most sites they are sold without one and that is a terrible idea.

 

The only reason I even mentioned the CPR overflow in my writeup is because that is what I am familiar with and know they will work great if "doctored up" a bit.

 

As you said - there are MANY solutions to the problem of not having a drilled tank and not being able to drill it for whatever your reason is. As long as the solution to having a sump without a drilled tank involves buying a Float Switch

[AZDesertRat]

I would take a Eshopps or Lifereef over a CPR any day of the week. Very reliable and no need for a pump.

 

I also disagree with the check valve in the return plumbing, check valves have no place in saltwater aquariums. They can, do and will fail so are really a false sense of security that should never ever be relied on to work. They are one of those things that gives you a warm fuzzy feeling and thats about it. As long as you keep your returns close to the surface of the display so only a small, very easily calculated amount of water backsiphons in a power outage and you maintain sufficient freeboard or spare room in the sump nothing else is needed or wanted to complicate things. Nothing to clean or maintain and as simple as it gets.