Am I making this complicated

[Charney]

I am getting ready to setup two 1,200 gallon tanks. They will be sitting next to each other. One tank will be a heavily stocked monster community tank and the second will house my aba aba. I really want to tie these two tanks together. This way the heavily stocked tank can benefit from the aba aba's tank. To do this I would need to have one tank elevated over the other to allow for easy water flow. Otherwise If I keep them level I worry they might not circulate well even with pumps. To elevate the one I tank I will need to build a cinder-block stand. Furthermore these tanks are fiberglass panels that need to be assembled and I imagine it will be much easier to assemble on the ground. Lastly there will be a drip. Should I just leave the two tanks as separate systems? The filtration will be air driven for both tanks so there will be no sump to join them.

 

[Backfromthedead]

I don't think you need to elevate one or the other. If you connected one to the other with two pipes, one with a submerged pump in one tank and just a submerged open channel on the other, the feed from the pump would raise the water level and pressure on the other pipe/channel on the output side, and water would rush through the open channel to equalize pressure between the tanks.

The problem would be if that open channel were to get clogged somehow. You would need at least one more channel to serve as an emergency overflow, located right above the waterline, so water would flow through there instead of flooding if the submerged channel is clogged.

 

[thiswasgone]

In my head I'd just plumb everything back to one large central sump but this doesn't sound like what you're really going for.

If you do the elevation route I would use a 1 submerged pump solution with an auto-siphon system but you'll need to work out how to auto-start/auto-jump the system if power goes out. Otherwise you'll have to drill like @Backfromthedead suggested which opens up a lot more options to join the two tanks.

 

[phreeflow]

I would not elevate one 1200 gallon over another with a cinder block stand. Also, I’d prefer separate systems in case there are ever any issues like equipment failure or sick fish, etc.

 

[Toby_H]

I don't think you need to elevate one or the other. If you connected one to the other with two pipes, one with a submerged pump in one tank and just a submerged open channel on the other, the feed from the pump would raise the water level and pressure on the other pipe/channel on the output side, and water would rush through the open channel to equalize pressure between the tanks.

The problem would be if that open channel were to get clogged somehow. You would need at least one more channel to serve as an emergency overflow, located right above the waterline, so water would flow through there instead of flooding if the submerged channel is clogged.

This.

3 pipes connecting the tank. Two below the water line, one above. The one above does nothing, unless one below gets clogged. It's your safety. Of the two below, put a pump on one and the other is a gravity fed return.

The bigger your pump, the bigger the gravity fed return needs to be. But your pump doesn't need to be huge. a 400gph pump will swap the tank volume once per 3 hours. Half that would do what you're looking for.

The tank receiving water from the pump will be the high pressure side. It's surface will be higher than the other tank. But your 1200 gallon tank will have such a vast surface area the elevation difference will be minimal. You're welcome to do the calculations, but it's going to be a fraction of an inch.

There are some functional risk. If you put a prefilter on the gravity fed line, it will add resistance and increase the elevation difference between the tanks. That we can't calculate as it increases as the prefilter clogs. And open pipe is the safer bet. But that will allow little fish to get through. If that's an acceptable loss in your eyes, I doubt your Aba Aba will mind.

But... you'll still have the third pipe as a safety. So it doesn't matter. But plan like you don't have a safety, and always have a safety.


Lastly, if you put them at different elevations you'll regret it for the rest of it's life. It'll look esthetically wrong. Even if you can live with it your wife will hate it. It'll make my neck twitch, but that doesn't affect you.

 

[wednesday13]

I would not elevate one 1200 gallon over another with a cinder block stand. Also, I’d prefer separate systems in case there are ever any issues like equipment failure or sick fish, etc.

+1…. This is a really good point IMO… equipment or tank failure is a big one. Sure would b nice to just flop everyone over to the other tank if theres a leak that needs repaired. Treating 1200 gal instead of 2400 is much cheaper as well if u ever need meds.

As for connecting them. Id just leave them both on the ground and run one higher water lever than the other. Put ur autodrip drain in the “lower” one to set the water height and pump water back up/over to the other tank. Only has to be 1-2” difference. Personally i think itd look cool to see it flowing down a level. Will give u current in there as well to turn it over. Id put bulkheads in the “higher tank” and just run the pipe right though a drilled hole in the “lower” one. No need for extra bulkheads or bothering really connecting them.

Always many options and ideas… nothing is permanent either. Can get em running one way and change as u go.

 

[Charney]

As for connecting them. Id just leave them both on the ground and run one higher water lever than the other. Put ur autodrip drain in the “lower” one to set the water height and pump water back up/over to the other tank. Only has to be 1-2” difference. Personally i think itd look cool to see it flowing down a level. Will give u current in there as well to turn it over. Id put bulkheads in the “higher tank” and just run the pipe right though a drilled hole in the “lower” one. No need for extra bulkheads or bothering really connecting them.

Thank you. Sorry having trouble following here

 

[jjohnwm]

The key is to have multiple large channels linking the two tanks. If your pump moves 2000gph of water and you consult some chart that tells you that this is the flow rate you can achieve with, for example, a single 3-inch pipe...don't put in a single 3-inch pipe. Put in 4 or 5 of them. Multiple pipes act as safety back-ups in case one or more get clogged. The greater the total cross-sectional area of the connecting channels are, the more easily water flows from one tank to the other, the less "head pressure" will build up between the two and the less of a difference in water levels will be apparent.

I've had numerous variations on this theme over the years, always set up (as you have stated yours will be) with independent backup filtration in each tank. In case something bad happens and you need to temporarily stop the interconnecting water flow, you just turn off the pump and remove enough water to drop the level below the connecting pipes. Both tanks keep chugging merrily away on their own.

One caveat: the more water you incorporate into multi-tank systems...the more cautious you should be about new fish introductions. If you are paranoid and don't add new fish often, and quarantine new arrivals for weeks or months...I'm raising my hand here!...then this idea is great.

If you can't drive past a fish store without buying something...if you are constantly making impulse purchases or "rescuing" fish or buying fish that you know nothing about...if you don't think that quarantine is important...if you just can't leave well enough alone...then I'd abandon this idea completely.