How Deep Do You Put Your Return Line Outlet

[Darwin stinton]

Was wondering how deep everyone places their return line outlets. It seems that everywhere I look in Stores, On-Line, and so on, the rule is to have them just skim across the top of the water, or just below. I've been thinking of placing my deep to get better turnover bottom up. Then just drilling a anti-siphon hole just below the water line. Thoughts Please.

 

[Crabs McJones]

Was wondering how deep everyone places their return line outlets. It seems that everywhere I look in Stores, On-Line, and so on, the rule is to have them just skim across the top of the water, or just below. I've been thinking of placing my deep to get better turnover bottom up. Then just drilling a anti-siphon hole just below the water line. Thoughts Please.

That would work as long as the hole is big enough to handle the pull back when your pump turns off. I did that with my hang on back return nozzle. Drilled a hole just under the water line but pointed the nozzle down pretty far, when I turned the pump off the hole sucked in air and broke the siphon.

 

[redfishbluefish]

There's also a reason to have flow at the surface....to agitate the scum off the surface. That's what I do.

 

[landlubber]

also consider that the tank is going to drain down to the point your return lines are sitting provided they're positioned above the bulkhead. what this means is that should the power cut to your return pump the lower the return lines are the more water is going to drain from your tank which could be disastrous if your sump can't hold the extra.

 

[ikanayam]

Thing about anti-siphon hole is you need to make sure it does not get clogged with salt, snail etc etc. Having the nozzle(s), usually split from one return into two, near the surface give a slightly higher safety margin against the back siphon flooding the sump.

 

[don_chuwish]

Mine are basically at the same level that the Synergy Reef overflow drains down to anyway. Maybe 1/2" below the surface. For other water movement in the tank you want powerheads - the return flow doesn't do enough to keep detritus stirred up by itself.

 

[hubble]

Mine are basically at the same level that the Synergy Reef overflow drains down to anyway. Maybe 1/2" below the surface. For other water movement in the tank you want powerheads - the return flow doesn't do enough to keep detritus stirred up by itself.

This

 

[K. Steven]

Right at the surface for agitation and gas exchange and for siphoning the least amount of water to the sump for feeding and power outages.

 

[ca1ore]

I don't use loc-line, or any other kinds of flow-robbing crap, rather a single 1 1/2" output, about 1/4" under the water surface firing directly down behind my rocks. Assuming you have adequate in-tank turnover and surface skimming, surface agitation is unnecessary.

 

[Fin]

I wouldn't trust a small anti-siphon hole. Most times they do work - most times.

Food for thought here, if you want your returns lower than usual...

 

[redfishbluefish]

Wow! I am so against in-line check valves, because they are doomed to fail and flood your house. However, the above video is down right brilliant. This is the only way I'd suggest using check valves. Again, I'm loving this use of check valves and trying to figure out how I could use this reverse check valve idea, even though I don't need it!

Great find @Fin .

 

[leahfiish]

Following because I made a stupid mistake and requested my return line to be drilled 3" from the top of my tank and my sump can't handle that extra volume. ;Facepalm

 

[ca1ore]

Yeah, done that! You can buy a few black PVC elbows to raise the output. Not ideal, but better than watering your floor.

 

[leahfiish]

That's what I was thinking of doing. I can probably hide it with a frag rack or something too.

 

[redfishbluefish]

Why not a tee with the check valve pointing straight up.

 

[leahfiish]

Wouldn't that make a huge mess if the check valve fails?

 

[redfishbluefish]

Wouldn't that make a huge mess if the check valve fails?

Then put an elbow at the top of the check valve pointing into the tank.

 

[Greybeard]

I like mid-water returns. You just have to plan them right. And no, I don't use, and won't rely on, back flow valves. One too many failures, never again. On my latest build, last summer, I purchased 'siphon stopper' returns from CustomAquarium, along with their H2Overflows.

The overflows I like, they work great... the returns, not so much.

Pic from initial setup:

See those two bits of angled plastic coming down from the top of the returns? Those are three sided, open on the bottom, and each has a vent running into it from inside the return. The idea is, when running, these have small jets of water coming through them, guided into the water by those bits of plastic. In freshwater tanks, I'm sure it works great. In saltwater, those jets of water drag air down with them, giving you a constant stream of bubbles in the tank, and causing all sorts of salt creep.

Here's a short vid I did when I first saw the problem. This is freshwater, and you can see how much water is spashing up on the rim of the tank. Imagine how bad it would have been with saltwater!


Anyway, I ended up cutting those plastic wings off, siliconing over the above waterline holes, and re-drilling a 1/4" hole in each, an inch or so below normal water level. Works, but you could do something similar with bits of PVC and loc-line a whole lot cheaper.

 

[Big G]

Here's a picture of what I did. I wanted surface agitation. First I just used pvc elbows. Then I tried using a diffuser. Neither had a good flow into the tank. So I attached a Loc-line with a flare. Perfect. Limited splashing up onto the screen above so not much salt creep. But got great air mixing and a wide dispersal of flow across the top of my 90. Hope this helps. Cheers!