So many overflow systems - still confused

[jgaepi]

I am ordering a 30x18x12 custom tank and trying to understand overflow systems. So many options.

 

I think I have narrowed it down to three options and want to get opinions based on the dimensions of my tank. 12 inch high.

 

BeanAnimal is recommended by PicO who is making my tank. GlassHoles 700 design has lots of good reviews. Or a bottom drain style but retrofitting my existing stand (but obviously can't go back after I cut it).

 

Is there a better system for a shallow tank?

 

Another key consideration, I am using a Reef Octopus Mini 80 sump that is only 12in wide. Would I realistically be able to stick 2 overflows plus emergency overflow into the Mini 80 sump?

 

Need good advice. Thank you.

[seabass]

It's a matter of opinion. I personally like a simple Glass-Holes overflow. It gets the job done, is pretty inexpensive, and has a nice clean design.

[jgaepi]

It's a matter of opinion. I personally like a simple Glass-Holes overflow. It gets the job done, is pretty inexpensive, and has a nice clean design.

Seabass, we chatted about the bean animal. Chris at PicO likes it because of the redundancy and silence but I am worried about getting all the pipes into the small sump.

 

Also, for my wife, I need to eliminate as much flood risk as possible.

[seabass]

The BeanAnimal is a good design. There is nothing wrong with it. However, it does require more space and plumbing (and $).

 

The risk of flood with a traditional overflow (like one the Glass-Holes overflows) is pretty small; it would require the overflow/drain to become clogged. However, if you keep the return chamber (and water level in this chamber) small, you can almost eliminate any chance of flooding.

[hey]

The BeanAnimal is a good design. There is nothing wrong with it. However, it does require more space and plumbing (and $).

 

The risk of flood with a traditional overflow (like one the Glass-Holes overflows) is pretty small; it would require the overflow/drain to become clogged. However, if you keep the return chamber (and water level in this chamber) small, you can almost eliminate any chance of flooding.

 

Yep, I run a siphon powered overflow which can (and most likely will fail) at some point, the single safest thing you can do is to size the return chamber of your sump with less gallonage than the leftover space in the display. Yeh your pump can fry but your floors won't be ruined.

[seabass]

Yeah, a clog will fry the pump no matter how big the return chamber is. It's just a matter of how much water you will pump into the display (onto the floor) before it happens.

[jgaepi]

Yep, I run a siphon powered overflow which can (and most likely will fail) at some point, the single safest thing you can do is to size the return chamber of your sump with less gallonage than the leftover space in the display. Yeh your pump can fry but your floors won't be ruined.

 

I am not super tech inclined so you have lost me a little. Return chamber with less space then the display overflow? How do I determine that?

 

Yeah, a clog will fry the pump no matter how big the return chamber is. It's just a matter of how much water you will pump into the display (onto the floor) before it happens.

 

Seabass, yeah, I want to avoid that. So how do I do that?

 

I bought this sump in advance: http://www.coralvue.com/reef-octopus-rs80-18-inch-pvc-sump

 

So how big should my overflow be?

[hey]

I am not super tech inclined so you have lost me a little. Return chamber with less space then the display overflow? How do I determine that?

 

 

Seabass, yeah, I want to avoid that. So how do I do that?

 

I bought this sump in advance: http://www.coralvue.com/reef-octopus-rs80-18-inch-pvc-sump

 

So how big should my overflow be?

 

I was saying the return chamber in the sump needs to be a smaller volume than the empty part at the top of the display in order to completely prevent the possibility of an overflowing tank due to a clog.

[seabass]

Seabass, yeah, I want to avoid that. So how do I do that?

 

I bought this sump in advance: http://www.coralvue.com/reef-octopus-rs80-18-inch-pvc-sump

 

So how big should my overflow be?

Normally you can design the sump so the return chamber is smaller; but in your case, the baffle is in a set position. However, you can still elevate the return pump (or lower the water level) to limit how much water is pumped in the event of a clog.

 

I'm not sure that I fully understand this picture.

The water should be spilling over the baffle, but it looks like the water level is below the top of the baffle (on both sides). I wonder if you have to seal the seems with silicone.

 

Do you know which return pump you are going to be using?

[jgaepi]

 

Do you know which return pump you are going to be using?

Not yet any recommendations?

[jgaepi]

 

I was saying the return chamber in the sump needs to be a smaller volume than the empty part at the top of the display in order to completely prevent the possibility of an overflowing tank due to a clog.

But if I go the bean animal route with an emergency overflow than this eliminates the clog concern.

 

Why wouldn't people go the bean animal route?

[Eckozulu]

A lot of people don't use the bean because it's a lot of drilling/holes. A more popular option is the herbie overflow. There are a lot of videos on YouTube for you to watch. Basically it's a bean with a main overflow at full siphon and a emergency drain. You use a gate or ball valve to "tune" the main drain.

 

As far as a return pump, I'm a huge fan of DC pumps. You can adjust the amount of flow without using a ball valve. Waveline, jaebo, reef octopus are a couple of the people who make it. I would also recommend using a check valve on the return to prevent a back siphon through the pump, when the pump has no power.

 

So the herbie is 3 holes, 2 1.25" holes in an overflow box and one 3/4" return where ever u want it. A 1.25" drain will give you about 900 gph turn over rate, which is aprox 30X your tank volumne.

 

Hope this helps.

[Eckozulu]

[tjp1014]

I have a glass-holes overflow and I am pleased how it works. Like seabass and hey suggested, my sump is configured so that if the overflow clogs, there is more than enough room in the display to accommodate the amount of water that will be pumped from the return section of the sump. Also, if the return pump fails, there is enough room in the sump to accommodate the back siphon from the return line. I don't have a check valve on my return line.

[seabass]

But if I go the bean animal route with an emergency overflow than this eliminates the clog concern. Why wouldn't people go the bean animal route?

Like I said, it's a good option (as is the Herbie). Why wouldn't someone use it? Because the threat of a clog is pretty minimal, and you can minimize the impact of a clog by making the return chamber smaller and keeping the water level down in this section. It's cheaper, less plumbing, and typically a smaller (cleaner looking) overflow box.

 

Not yet any recommendations?

The reason I ask about a return pump is that the overflow and pump work together. So have you decided on flow rate or type of overflow yet?

[NirvanaandTool]

Personally I think Bean > Herbie > Durso. I've had all 3 and currently have a Herbie now in a 90RR. Beans and Herbies move massive amounts of water via siphon and are generally quieter than a Durso.

 

Redundancy with an emergency drain is never a bad thing. I've had a flood with a Glassholes before (turbo snail camped out right in front of the drain bulkhead) so if you go this route, make sure the overflow is covered with eggcrate or something similar.

 

If you are concerned about the amount of space taken up by the overflow, make it an external bean. A small slim internal overflow box is all that is required inside the tank with maybe 2 drilled holes that would fill a larger box on the back that would house all the plumbing.

[markalot]

I don't understand how a tank can flood if an overflow gets clogged. I do understand how complex this all seems from someone who has never done an overflow before.

 

Looks like I'm restating what has already been said.

 

1. Understand the importance of having a separate return section in the sump just large enough for a return pump. This area should be fed water over top of a baffle so if the overflow gets clogged and the sump water level drops below the baffle the return area will quickly be pumped dry.

 

2. Make sure not to overfill the sump with water (remember the baffle above?). The quicker the return section runs out of water the less chance you will overflow the display. Ideally you will test this when filling the tank, with a quick shutoff switch so you don't actually overflow the display if you guessed wrong. This is more difficult with nano tanks.

 

3. Every hole drilled in the tank is a risk. Use the simplest overflow you can get that has a noise you can tolerate. I use the Dursos that came with my tank. It's not silent by any means but the tank is not in an area where it matters.

 

I have a glass-holes overflow and I am pleased how it works. Like seabass and hey suggested, my sump is configured so that if the overflow clogs, there is more than enough room in the display to accommodate the amount of water that will be pumped from the return section of the sump. Also, if the return pump fails, there is enough room in the sump to accommodate the back siphon from the return line. I don't have a check valve on my return line.

 

^^

[GTi]

I don't understand how a tank can flood if an overflow gets clogged. I do understand how complex this all seems from someone who has never done an overflow before.

Even if the overflow is blocked, the return pump will still be filling the display tank. Depending on how much water is available in the sump/return chamber, and the unused capacity in the DT, you may get too much water in the DT and it will spill over.

[hey]

Also your auto top off is fed to the return chamber, its a good thing to keep a redundancy float switch for the topoff in the display so if the display level rises the top off wont come one. Essentially the top off is an extension of your return chamber volume.

[markalot]

Even if the overflow is blocked, the return pump will still be filling the display tank. Depending on how much water is available in the sump/return chamber, and the unused capacity in the DT, you may get too much water in the DT and it will spill over.

 

Yep, which is why the return chamber and the sump water level is so critical. I think a lot of people neglect the test to set sump level and run their sump at some arbitrary level that looks good and then are shocked if it overflows. I tested by having the display level lower than the overflows and then measuring how much the water rose before the return chamber was emptied. I have a big tank so it's not as critical as it is for smaller tanks.

 

What I don't have is float switches to turn off the sump if the water level drops too low. I run a timed topoff, not float based, so I get around the topoff float issue.

 

Oh, and of course the reverse test is to make sure you don't overflow the sump if the pump fails and the display empties into it. That ended up being what set my water level, not the return chamber amount.

[hey]

Yep, which is why the return chamber and the sump water level is so critical. I think a lot of people neglect the test to set sump level and run their sump at some arbitrary level that looks good and then are shocked if it overflows. I tested by having the display level lower than the overflows and then measuring how much the water rose before the return chamber was emptied. I have a big tank so it's not as critical as it is for smaller tanks.

 

What I don't have is float switches to turn off the sump if the water level drops too low. I run a timed topoff, not float based, so I get around the topoff float issue.

 

Oh, and of course the reverse test is to make sure you don't overflow the sump if the pump fails and the display empties into it. That ended up being what set my water level, not the return chamber amount.

 

My method is, measure the depth of the empty space in tank above the water line x aquariums footprint... keep return chamber capacity smaller than that, sometimes its easier to put the pump on a stand rather than make the chamber super super small.

[markalot]

My method is, measure the depth of the empty space in tank above the water line x aquariums footprint... keep return chamber capacity smaller than that, sometimes its easier to put the pump on a stand rather than make the chamber super super small.

 

Great idea, and it might even keep the pump cleaner being off the bottom of the sump.

[hey]

Great idea, and it might even keep the pump cleaner being off the bottom of the sump.

 

My "stand" is actually a few ziplock bags filled with sand. It thoroughly dampens the vibrations from a cheapo magdrive pump that are notorious for noise on some models.

[Mr. Microscope]

I like the herbie style. Simple design and can be dead silent.

[Eckozulu]

As far as having minimal water in the return to prevent overflow in the DT, ATO is a major player for that. I run at least a 5g resivoir and I don't want any floats in the DT, kinda defeats the purpose of the sump.

 

Good luck with your choice!!!