DIY help connecting tanks

[JakeNova]

Im posting this here before I finalize anything. I need to connect these tanks before next week when life is going to get BUSY.

My plan is to create a continuous siphon overflow with a return pump in the 15g cube.

I will probably diy a corner overflow on the cube to protect the return pump or buy one

If anyone has recommendations or knows better than me I am open to listen.

The 15g cube already has a huge population of pods. I literally have been raising amphipods in it. Some are huge like the size of a sexy shrimp.

I also have two pieces of the same macroalgae that i put in each tank. The 15g cube macroalgae is bleaching while the piece in my display is coloring up quickly. Ive moved these macros to and from each aquarium to test and see what happens. Connecting tanks is the best move now. Especially because id like to reduce maintenance on something thats basically just a refugium.

I am aware I should match water qualities before.

 

[JakeNova]

Wip

 

[sgdnycct]

I’ve thought of doing something like this in the past. One question I have is have you thought of the height difference? If the power goes out the taller tank will overflow the lower one.

 

[JakeNova]

I’ve thought of doing something like this in the past. One question I have is have you thought of the height difference? If the power goes out the taller tank will overflow the lower one.

The idea is if power goes out, the return pump stops then the siphon will be forced to stop when the water level reaches below my overflow. Check valve on the return so water cannot siphon backwards. Ill lower the water level in the 15g definitely

 

[JakeNova]

I’ve thought of doing something like this in the past. One question I have is have you thought of the height difference? If the power goes out the taller tank will overflow the lower one.

Im not sure ill have high enough flow rate with the tubing I have. Going to look for maybe a 1" diameter tube to run through the pvc tomorrow

 

[UncommonSense]

Check valve on the return so water cannot siphon backwards.

I wouldn’t trust a check valve to keep water off your floor…

The recent manned moon flyby on the Artemis II spacecraft had helium system issues, primarily related to malfunctioning check valve(s)… — that is to say, even NASA cannot get a check valve to work 100% reliably in 2026!

A better alternative (no moving parts) is designing/positioning your return nozzle in such a way that it slurps in air during a siphon event, ideally in conjunction with a 1/8”-1/4” hole strategically drilled in the in-tank return pump plumbing (in the tank you are pumping water back to) to also slurp up air, preventing that siphon even if the return nozzle is accidentally bumped deeper underwater!

 

[sgdnycct]

Agree I wouldn’t trust the check valve. I’ve heard horror stories.

Also, you don’t want it set it up in a way that reduces the water volume in the small tank too much nor that the siphon might break. Besides being a PITA to restart, if you’re not around it could over drain the smaller tank.

Can you raise the small tank so they’re at the same water line height?

 

[BeanAnimal]

Are you open to drilling one of them for a bulkhead?

 

[JakeNova]

Im posting this here before I finalize anything. I need to connect these tanks before next week when life is going to get BUSY.

My plan is to create a continuous siphon overflow with a return pump in the 15g cube.

I will probably diy a corner overflow on the cube to protect the return pump or buy one

If anyone has recommendations or knows better than me I am open to listen.

The 15g cube already has a huge population of pods. I literally have been raising amphipods in it. Some are huge like the size of a sexy shrimp.

I also have two pieces of the same macroalgae that i put in each tank. The 15g cube macroalgae is bleaching while the piece in my display is coloring up quickly. Ive moved these macros to and from each aquarium to test and see what happens. Connecting tanks is the best move now. Especially because id like to reduce maintenance on something thats basically just a refugium.

I am aware I should match water qualities before.

Ive done some looking into it. My original idea simply would not work standalone, its high risk with little potential for maintenance. My idea now is to copy the overflow ideas from youtube but scale it up a bit.

Today, I made this tube with a barbed male connection> female>pvc>ball valve>. I couldnt find a T that was the right size and i forgot i needed it. So i put it all together and realized. WOW WHAT A GREAT SIPHON ILL HAVE WITH THIS BALL VALVE.
So i need to find a T that works so i can use the ball valve to burp the potential air build up in siphon. The T will create the highest point where any air will trap and I can simply burp it. (In my head it works)

This is the idea going forwards. I have to cut out the overflow point. Drill out holes for the tubing. Fix the tube so I have a T on top.

I also got plumbing for the return pipe but im not home.

 

[BeanAnimal]

A siphon is under vacuum, not pressure. Opening the valve will allow it to pull air in, not burp it out.

 

[JakeNova]

Agree I wouldn’t trust the check valve. I’ve heard horror stories.

Also, you don’t want it set it up in a way that reduces the water volume in the small tank too much nor that the siphon might break. Besides being a PITA to restart, if you’re not around it could over drain the smaller tank.

Can you raise the small tank so they’re at the same water line height?

I think I will have the return line out of the water and well above the actual water line and well secured. Im going to run the pump at the lowest setting and pray it works. I have quick access to the plugs if i need to turn off the return pump

 

[JakeNova]

A siphon is under vacuum, not pressure. Opening the valve will allow it to pull air in, not burp it out.

Youre right. I might just take this out completely and run just the tube

 

[BeanAnimal]

Are you opposed to drilling one of the tanks?

 

[JakeNova]

Are you open to drilling one of them for a bulkhead?

I have thought about it. Its really the way to do it but I dont plan on keeping these tanks for too long. I want to upgrade in a couple months. This is mainly so my copepods have a safe haven. My 29g display is too small and i bought a melanarus wrasse which has devastated the populations of every microfauna i have. The 15g tank has been literally a test for macroalgae and microfauna but its needed. I have a fiji cube refugium but i have no space for it. This is my solution.

 

[JakeNova]

Are you opposed to drilling one of the tanks?

I would lower the water level in the 15g then drill that if anything. Its totally doable. Im open to hear your idea

 

[JakeNova]

A siphon is under vacuum, not pressure. Opening the valve will allow it to pull air in, not burp it out.

I think i will use a syringe and silicone tubing on the ball valve end to attempt my idea. So when i need to "burp" the siphon. When i attach the silicone tubing, pull in the extra air with the syringe then do the same whilst opening the valve. Even if i ruin the siphon it is any easy access to also restart the siphon so it wont really hurt. I am learning

 

[Mebbid]

I have thought about it. Its really the way to do it but I dont plan on keeping these tanks for too long. I want to upgrade in a couple months. This is mainly so my copepods have a safe haven. My 29g display is too small and i bought a melanarus wrasse which has devastated the populations of every microfauna i have. The 15g tank has been literally a test for macroalgae and microfauna but its needed. I have a fiji cube refugium but i have no space for it. This is my solution.

Honestly, you're risking a flood. If it were me, I'd get a HOB refugium and use that instead. But yeah, a 29g is quite a bit too small for a Melanarus, you're going to have to make sure it's eating alternative foods to just pods.

 

[JakeNova]

I have thought about it. Its really the way to do it but I dont plan on keeping these tanks for too long. I want to upgrade in a couple months. This is mainly so my copepods have a safe haven. My 29g display is too small and i bought a melanarus wrasse which has devastated the populations of every microfauna i have. The 15g tank has been literally a test for macroalgae and microfauna but its needed. I have a fiji cube refugium but i have no space for it. This is my solution.

Honestly, you're risking a flood. If it were me, I'd get a HOB refugium and use that instead. But yeah, a 29g is quite a bit too small for a Melanarus, you're going to have to make sure it's eating alternative foods to just pods.

I have a hob refugium but it was aquired well after I had the 15g set up next to my 29g. To be honest. The guy who said he'd sell me the refugium said he would have it ready months before he actually did. So i set up the 15g hastily because this guy didnt hold up his word. I started to move to connect these tanks then he finally brought me the refugium. At this point I dont care. My melanarus requires more than the display can provide so i will improvise fow now. This is not permanent and i spend lots of time with my tanks.

 

[JakeNova]

I have thought about it. Its really the way to do it but I dont plan on keeping these tanks for too long. I want to upgrade in a couple months. This is mainly so my copepods have a safe haven. My 29g display is too small and i bought a melanarus wrasse which has devastated the populations of every microfauna i have. The 15g tank has been literally a test for macroalgae and microfauna but its needed. I have a fiji cube refugium but i have no space for it. This is my solution.

Honestly, you're risking a flood. If it were me, I'd get a HOB refugium and use that instead. But yeah, a 29g is quite a bit too small for a Melanarus, you're going to have to make sure it's eating alternative foods to just pods.

I feel like im babysitting my tank now with a wrasse and im also seeing quickly. The wrasse responds to prepared foods when it is actually hungry. If it is not really hungry then it will ignore all food and just hunt for pods. At first it ate all prepared foods fluently, as time goes on the wrasse has ignored prepared foods and has focused on hunting pods. Pods which levels are reduced signifcantly

 

[JakeNova]

I have thought about it. Its really the way to do it but I dont plan on keeping these tanks for too long. I want to upgrade in a couple months. This is mainly so my copepods have a safe haven. My 29g display is too small and i bought a melanarus wrasse which has devastated the populations of every microfauna i have. The 15g tank has been literally a test for macroalgae and microfauna but its needed. I have a fiji cube refugium but i have no space for it. This is my solution.

Honestly, you're risking a flood. If it were me, I'd get a HOB refugium and use that instead. But yeah, a 29g is quite a bit too small for a Melanarus, you're going to have to make sure it's eating alternative foods to just pods.

I feed various foods daily but my problem with the melanarus is that if my pod population doesnt sustain then it will slowly decline. I do not have an auto feeder and its been weening away from pellets. Im not sure if its because i had so much microfauna it had a buffet when I first added it or not but its responded less and less to the foods I add. I enrich all my food with vitachem and selcon. I had a huge pod population in my tank so i was confident but i was wiped out in a week.