Display Fuge (Need some Help)

[CosmicCanine]

Okay, So if you didnt know, my 29G mixed reef is starting to be more and more demanding. Its fully established, And have phosgaurd, and carbon running now. (thanks to kat) I have a fluval spec that i want to place on a stand next to my main display (same height) How would i go about getting water from the 29 to the spec, aand from the spec to the main? i want it to be lowish flow so i can keep miracle mud in there, as well as chaetomorpha... i have a ecoxotic tricolor parr 38 to put over the fuge (blues, reds, whites) Thanks for the help.

[Beer]

I see several possible issues with this.

To save a three page reply with several more pages of contingencies:

1. Does your tank currently have a sump?

2. Will the water level of the spec be lower than the display?

3. Are you okay with leaving the water level in the spec low enough to handle the volume of water that would drain from the display during an outage or pump failure?

4. Are you dead set on having them at the same level? Would you be okay with setting the spec slightly higher than the display? (Ideal solution in my mind. Small pump feeds the 'fuge and gravity drains back. Preserves the life that transfers from the fuge to the display and poses the least risks during drain blockage (if you have a backup drain), pump failure is a non-issue, as is a power failure)

[ajmckay]

So I'm sure someone smarter than I am will chime in but I see no truly ideal solution. The safest will always be to use gravity in some manner.

 

Basically you're talking about connecting 2 separate tanks together without the aid of gravity. 3 ways to accomplish that I can think of.

 

1) 2 pumps. Have one pump going from the smaller tank to the larger and one going from the larger to the smaller. Very risky I wouldn't do it. One gets out of sync and you're effed.

 

2) Put one tank higher than the other and use an external overflow box such as the eshopps pf nano. This could work. Basically you would have the smaller tank on a stand so that the water level is above the 29g. Water pumps up from the 29g to the 5g and it drains back down. Not sure how high you would need to have it though... You would probably need to do a bit of testing with this method. You could have the 29g drain into the 5g but as mentioned you would need to keep the water level low enough to deal with the excess water from the 29g. I calculate this at roughly 1 gallon per 1/2" of water in the display.

 

3) Connect the 2 tanks via a straight passage. Use a stand to align the smaller tank so that the water level of both tanks will be the same. Then drill a hole in each tank so that they connect. (doesn't need to be huge, just big enough to handle the water flow you'll put through it so probably 3/4" bulkhead). Then use a bulkhead and connect the 2 tanks. They will need to basically be touching. You would need to use a thick o-ring or gasket seal of some type between the tanks, something pretty thick and squishy that is larger than the hole you drill. Then you put a pump (with an overflow so you get some surface skimming!) into the 29g and pump into the 5g. Because the 2 tanks are connected they will keep the exact same water level and there's never a chance of overflowing as long as you don't let the passage between the 2 tanks become blocked. To mitigate this small risk you could upsize the bulkhead to 1" or you could put strainers on each end to prevent thinks like snails from getting stuck.

 

Like this:

 

Good luck.

[Weetabix7]

Ok, I'm not an expert on this, but I have done this before in a super basic way.

In my case, I put 2 tanks that were the exact same size next to each other on a counter, put a U-tube connecting both of them (with one side of the u-tube in each tank) and had a powerhead/pump in one tank that pumped water into the other tank.

The u-tube would keep the water levels even between them.

[CosmicCanine]

The spec will be lower than the main tank... i do not have a sump. Im doing this as a means of nutrient export. Im going to have chaeto in there as well as a mangrove... it will be lit with an ecoxotic tricolor par 38.

[Beer]

To run it safely, you are going to have to set it up like a normal sump, just beside the display instead of under.

 

You need some type of overflow, just sized a lot smaller than you would normally use since you are shooting for low flow, which will be nice as it will be a lot smaller and take up less room. You can use valves to throttle the flow as well.

Since the tank is established, I'm sure you don't want to go drilling it, so a HOB type overflow is probably going to be your best option. There are other methods without drilling, but this is the simplest and cleanest method I am aware of (as well as fairly cost effective. There are a lot of inexpensive options out there, a bunch offered by forum sponsors here). There are some things to be aware of when using a HOB overflow, like using an airlift pump to minimize the risk of air being caught in the overflow and restricting the flow rate. I've never used one, so I'm not sure which designs stay filled during a power failure and which designs require repriming to get them going. Unless someone else chimes in here, you'll have to do a little research on that. One that requires priming is going to require a self latching normally open relay to power the pump so the pump doesn't start up with the overflow not functional (you definately want to go with a design that stays filled to minimize problems).

 

Make sure you install backup drains so if one gets clogged, you don't pump the sump dry and flood the room. I usually make the backup oversized and set it up so it will be noisy (outlet above the water surface in the sump) to alert me when there is an issue with the main drain. I still frequently check to make sure everything is functioning properly.

 

The level in the sump is going to have to be low enough to take the surge volume from the display when the pump is off to prevent overflowing the sump.

 

 

Any method not relying on Gravity is going to need backups, redundancies, and failsafes to prevent issues. All added cost and complexity.

Tuning two pumps to match flow rates is going to be difficult, as biofilm builds up in the piping or if an animal crawls across the intake screen, flow rates will change. One pump failure will cause flooding and pumping one of the tanks dry. You could set up backup pumps and level sensors or just level sensors to shut the system down if there is a failure, but it doesn't guarantee that it will be failure proof and will require periodic testing to verify it is working properly. Either way it's a bunch of unnecessary added cost and too prone to flooding if there is a pump failure, change in flow rates, or if one pump doesn't immediately start up properly after a power loss.

 

 

I know you already have the Spec, but it may actually be more cost effective to go with a HOB style refugium. It doesn't sound like you are intending to run it as a 'fuge, but this may suit your needs pretty well. It may not have as large of a volume as the Spec and access may not be as easy as a sump sitting next to the display, but they are intended to have low flow, usually include a pump (some are air driven), require no additional plumbing or setup, are out of the way, and you don't really need to worry about the looks of what is going on inside there as it isn't 'on display'. The mangrove will still be visible above the tank, although lighting may require a different approach. They also gravity drain, so what ever critters start growing in there will make it to the display without getting chopped up by the pump.

 

 

On a side note, are mangroves really all that great at nutrient export? I was under the impression that their slow growth rate makes them pretty limited at nutrient uptake, at least at the nutrient levels we keep our tanks at. They are usually located around tributaries, which are extremely nutrient dense. They also require fairly intense lighting at a different Kelvin temperature than what is used in reef tanks. I could be misinformed about their nutrient uptake ability though. They are cool and a little different than what you see in the average reef thank.