Overflow Chamber

[Kuon]

Hello all,

could you please help me with creating overflow chamber? I am not sure about right dimensions.

Aquarium: 178x80x70cm (80cm width)

I would like to create overflow with a sump. Overflow will be Herbie type (3 holes in bottom - 2 outlet, 1 inlet. Detail of chamber and holes attached. I have as well make a photo of bulkhead I want to use. The sump will be placed under aquarium.

Is the chamber big enough? Is space between holes (3cm) enough?

In regards to regular maintenance. Is necessary to be able to reach with hands to bottom of overflow chamber? After I install aquarium it will be pretty difficult to place hand at the bottom of overflow (will be possible but pretty hard).

Thanks for your responds in advance.

[Ron Reefman]

I've had fish, snails, crabs and even a serpent star get over the weir and down to the bottom of my overflow. Being able to reach in can have it's advantages.

[ThisGuy12]

Also, your holes should be one full size from the outer edge or you risk cracking the glass.

I had my tiger goby get into my overflow chamber (full wall overflow) and he was living in there for what I assume is days before I noticed him and put him back into the main.

Also, I placed snails and crabs in my overflow chamber to eat all the excess food that collect there. Was worth it, the chamber is virtually spotless.

Sent from my A0001 using Tapatalk

[Kuon]

I have reconsidered holes distance from edges. Is it better now? Should I change anything else?

With hand I am able to reach bottom - no problem to lift up animals and put it back to display tank. But for example screwing bulkheads inside chamber would be problem (after I install aquarium to place where it should sit).

[Lsufan]

It's better but it's still not ok, u need 55mm from the edge of the glass & between each hole. U will have to make the overflow a little bigger. The longer the weir the better it is for surface skimming also. So the longer it is the better it will be.

[Kuon]

Ok, I did 5,5cm holes distances, chamber is a few cm bigger. Ok like this? I understand advantages of having bigger chamber on the other hand I dont want it to take a lot of space from display tank.

Is this a good compromise?

[LXXero]

If you are doing a herbie, the full siphon can simply be a strainer coupled to a length of PVC, kept at least 6" below the level of water in the weir. This won't need much space at all.

The emergency should just be a straight-pipe on a herbie. Again, this doesn't need much space.

Just make sure you have enough room to reach in and grab the PVC and stuff, so you can pull it out without fighting with it too much.

And i'm not sure what you plan to do for the returns, but leave enough room for whatever you do there.

I would not screw anything into the bulkheads. Use slip bulkheads. Simply slip the standpipes in, friction fit. Even if they leak, guess where the water goes? Down the drain again. It's fine.

You shouldn't have to screw anything inside the chamber. The bulkhead nut should go on the outside of the tank and you can generally tighten it entirely from the outside...In regards to the PVC fittings, I usually use slipxthread or slipxslip bulkheads. Slip x thread for bulkheads that i might want to remove later or whatnot. That's thread on the outside though, NOT the inside. I ALWAYS do slip inside, and leave it unglued. Friction fit. Again, if it's inside the overflow box, the only place water could go is down the drain again, a tiny drip down the drain is not gonna hurt anything, and makes maintaining it about 10x easier than trying to unthread a fitting from a bulkhead. And 1000x easier than cutting off glued PVC!

[Kuon]

TO LXXero: understood, I will not screw anything inside. One question in regards to bulkheads (slipxthread). Do you glue it with silicon before you screw it from outside the tank? Or is it enough only to screw it tightly? For standpipes I understood not to use any glue but for bulkhead itself I am not sure.

[LXXero]

TO LXXero: understood, I will not screw anything inside. One question in regards to bulkheads (slipxthread). Do you glue it with silicon before you screw it from outside the tank? Or is it enough only to screw it tightly? For standpipes I understood not to use any glue but for bulkhead itself I am not sure.

No, you don't glue anything in that regard. The bulkhead flange has a rubber gasket under it. This is what seals the bulkhead to the tank. Generally, they say: tighten the bulkhead nut as much as you can by hand, then another 1/4 turn with a wrench. You often need a huge adjustable wrench for this. Don't over-tighten, you don't wanna crack the glass.

Only difference between slipxslip and slipxthread is how you attach your plumbing to the bulkhead. With slipxslip, you'd glue the plumbing to the bulkhead. The bulkhead does not get glued to the tank.

On slipxthread, you attach the pipe to the bulkhead via threads on the inside of the bulkhead. Not the threads on the outside. Those are strictly for holding the bulkhead to the tank via the bulkhead nut.

On a slipxthread bulkhead, you could use teflon paste to prevent leaks. I just use teflon tape though. For me, it's worked just as well. Others here swear by the paste, but it is harder to find, you will have to buy that stuff online. You can search here for tons of threads about sealing PVC threads, and all the various methods. You wouldn't use that on the bulkhead nut though. You want that to be dry so it has the friction to hold the bulkhead to the tank. This is only on the PVC pipe threads that you thread into the bulkhead that you would be doing any sort of paste or teflon tape at all. Again, don't overtighten here either, as you can crack/split the bulkhead. Teflon acts like a lubricant, which makes it easy to over-tighten the male fitting into the female threads, as you imagine that can cause it to crack or split.

[Anthony357]

pre drilled are the way to go!

[Kuon]

LXXero: thanks a lot for your explanation. I will definitely follow it.

Anthony357: pre-drilled, you meant to buy tank with drilling already done,correct? Yes I will not do it myself.

[ThisGuy12]

I siliconed around the flange of my threaded bulkheads inside my overflow, my 2" herbie bulkheads were HUGE, 1 easily handles the flow, the emergency is just "there" in case of a major problem (blockage). I don't see a blockage every happening with a 2" drain but you never know. I do have some rather large Strawberry Top Hat Snails.

I figure the silicone ads a secondary protection against leaks, if I ever need to change the bulkheads I'll cut them out and replace them.

I threaded my herbie pipes into the bulkheads snuggly fit hand tightened the short pipe is +/- 6" beneath the Overflow water line with a strainer on it. I have caught small fishies hanging out in my overflow chamber already a few times lol, one lived in there for at least a week while I was out but did fine.