Preventing Backflow Through Return and Make Drains Fish Safe

[Steelcube]

I have two 1" drain bulkheads on either side of my aquarium and one 3/4" return. All three are just bulkheads and I'd like to add fish once the tank is cycled and not worry about the fish taking a ride into the sump but I'm not sure what path to take.

1) Currently the return pump valve is closed a lot because opening it more requires me to add more water. The problem with that is that I noticed when I first started, topped off, then stopped the return pump the check valve had failed and I was going to overrun the sump. I'd like to increase return flow but I'd need to raise up where the return line is to prevent excessive backflow through the return. I'm not sure if I should add some elbows to raise it up or if I can just use some loc-line that arcs upward. I'm thinking using elbows might be most reliable.
2) I'd also like to an overflow box for the drain lines. I was tempted to use only one of the drains and install an internal overflow box with a main drain and backup like eshopps but I'm worried it won't fit and will hit the top of the glass ledge in the tank. Now I'm thinking about getting an overflow box with backing and drilling it myself. If I did this I'd put one on each side at the same height. I kind of like this idea but I'm having trouble finding this. Any recommendations?

In the meantime I plan to put loc-line w/splitter on the return, a strainer on each drain line, keep my return lined closed a lot and hope my check valve works (it has so far).

 

[outhouse]

You need a plastic screen

I made plexiglass covers for my drains, and drilled holes in return so it sprays in drain when running and when pump is off it breaks the syphon. The little hole needs cleaned out twice a years.

 

[Steelcube]

You need a plastic screen

I made plexiglass covers for my drains, and drilled holes in return so it sprays in drain when running and when pump is off it breaks the syphon. The little hole needs cleaned out twice a years.

I'm not sure I follow. I agree I need screens for my drains. I'd like to get overflow boxes with comb looking overflows. But not sure I understand how drilling holes in return spray into the drains... as long as the water level is above my return there's potential to drain back through return, even if it's connected to the drain. Illustrations may be helpful.

 

[JGT]

Rather than drilling holes in my loc-lines to break the siphon, i simply pitch them up so they are just below the top surface, pretty much at the height of the overflow weirs. When the pump goes off, it drains to the point where the returns are above the water line and it breaks the siphon.

 

[outhouse]

I can re explain. My return lines go up through the middle of the drain, which is not the same as your set up, which I think is plumbed going up and over the rim of the tank, or separate from your drains.

 

[Lost in the Sauce]

It seems like the simplest thing here is go straight out of your bulkhead to some lock line and have the lock line drilled with a siphon break right below the running water level.

 

[Water Dog]

For your drains, grab some flat strainers..,

Low Profile Bulkhead Overflow Strainers

Low profile strainer that extends fractions of an inch past the bulkhead itself. Prevents fish, snails, and other tank inhabitants from getting sucked into your plumbing, sump or pump and subsequent damage. Slip Low Profile Strainer - Used to slip inside of a slip bulkhead Thread Low Profile...

www.bulkreefsupply.com

Then for your return line, as suggested before, grab some locline and have the nozzle just below the water’s surface. As you can see in this photo, the RFG nozzle is even with the bottom of the weir teeth which would be just below the surface of the water. Articulate the return outlet properly ear the surface of the water and no drilling will be necessary for the siphon break.

 

[Steelcube]

I can re explain. My return lines go up through the middle of the drain, which is not the same as your set up, which I think is plumbed going up and over the rim of the tank, or separate from your drains.

Okay, I think I follow. I'm not sure that would help me here.

 

[Steelcube]

Thanks everyone. I'm going to follow the advice to have return locline go up to be just below where water level is. My main concern was if it's possible for leaks in the locline but sounds like that's very unlikely.
I really like those low profile strainers but I couldn't find any 1" slip in stock.
Edit: I was able to find those strainers in stock!

 

[bevo5]

I’ve drilled siphon breaks but I would get a little worried about coralline or something else closing them up eventually.