Noisy/Gurgly return

[bipedstites]

I have a 120 gallon tank with a 1400 GPH return pump. I drilled a 2 inch outflow hole and two 1.5 inflow holes. For the outflow inside the tank, I have a 90 degree angle connected inside pointing straight up. When the water flows into the outflow, it creates a 1 inch tall vortex. The water does not stay level with the top of the pipe. It is definitely keeping up with the pump because the overall water level stays consistent. On the outside of the tank, the outflow has a T connector, one goes down to the sump and the other end going straight up. The upper part of the T is capped with a 1/4 inch hole. The outflow pipe going down to the sump is 2 inch pipe all the way with only 45 degree turns.

The gurgling noise is loud. Is the gurgling caused by the vortex? Would a screen on the top of the output break the vortex? Is the 1/4 inch hole too small? Would a small overflow box help? I tried to tell my wife this morning that the ocean is also loud. That didn't work.

[evsalty]

First off I want to say correct terminology is KEY to getting proper diag/responses. The outflow, as you called it, is referred to as the drain side. The inflow, again your terms, is the return side.

Yes the vortex is probably your main cause for the noise issue. The reason you are seeing a fluctuation at the drain elbow (90* angle) is due to this vortex. An overflow box and an down turned 90 elbow would help with the vortex but you might still have some noise if you still have an air/water mixed drain. Siphon drains are completely quiet but you should always have a backup drain that is slightly above your water level in your overflow box. The tee and it's 1/4" hole are used to help the air escape out of the drain line but in this case you are pulling in too much air.

[bipedstites]

Originally Posted by evsalty

First off I want to say correct terminology is KEY to getting proper diag/responses. The outflow, as you called it, is referred to as the drain side. The inflow, again your terms, is the return side.

Thanks, even after a year I am still learning.

Yes the vortex is probably your main cause for the noise issue. The reason you are seeing a fluctuation at the drain elbow (90* angle) is due to this vortex. An overflow box and an down turned 90 elbow would help with the vortex but you might still have some noise if you still have an air/water mixed drain. Siphon drains are completely quiet but you should always have a backup drain that is slightly above your water level in your overflow box. The tee and it's 1/4" hole are used to help the air escape out of the drain line but in this case you are pulling in too much air.

I suspected that this might be the problem. This will be a simple fix. Won't have to worry about my fish ending up in my sock filter any more.