If you're following
my thread over in the member tank discussion, you'll know that I'm frustrated with the amount of noise I'm getting from my hang on back overflow.
I've spent the better part of the last month trying to come up with a solution, and thought I'd found it over on the Durso Standpipe site, where he showed
a modification that used a Durso standpipe with an external overflow.
I disassembled things last night and took this photo of my version of this mod:
I drilled a hole in the side of the overflow and where you see my hand is where the T fitting would normally go. I've got about two inches of pipe going up, with a piece of hard tubing glued into a cap. Going down is about 24" of pipe that goes into a 45 degree fitting into flex tube into my
sump.
The problem I've been having is getting the airflow hole just right. If there's too little airflow, it cycles quickly between siphon and flush, very loudly. If there's too much airflow, the pipe drains more slowly. The extreme end of that is to remove the top cap, which causes the flow rate to be extra slow and for the water to overflow the top of the tank.
I've been trying to come up with the perfect airflow hole and haven't been able to get it dialed in just right. What ends up happening is the drain works well for a while, then about every five minutes, I get the flush sound. Doesn't sound too bad, other than when it happens during dinner (the tank is in the dining room).
On the Durso site, he says that if you're getting the flush, it's usually because of back pressure in the drain line, not air hole size. However, in my case, there's virtually no possibility for back pressure since there's only one 90 degree fitting and a smooth curve into the
sump. The connection into the
sump terminates above the water level, so that's not contributing to back pressure either.
Troubleshooting link here, check the first item.
The only thing I've gotten to work fairly reliably is to reduce the flow on my pump. (Side note: without the drain pipe installed, the overflow can handle way more capacity than the pump I'm using). This isn't a very good long term solution as I want to have as much circulation through my tank as possible.
Over at Premium Aquatics, I found a
Stockman Aqua-Silencer made for overflows. The two comments say good things and the price is not that bad. I'm curious if anyone's tried using one of these. My plan would be to plug up the side hole and go back to using the bottom hole on the overflow.
Besides the noise, my other problem is that the water level in the tank is too high for my liking. It's constantly right at the top, to the point that you can sit on the floor and look up into the water to see the black plastic of the top border just barely submerged. I think the cause of that is the height I drilled my hole for the side opening. The Premium Aquatics overflow thingie looks good here since I'm guessing that it sits a little lower.
I'm open to any suggestions on these problems. I've been pulling my hair out trying to figure it out. Of course, I should have bit the bullet and just drilled the tank when it was empty. I can't imagine I'm the only one with this issue. I can imagine that others aren't as retentive as I am about extraneous noise, but I don't think I'm totally overboard here.
Thanks,
-Chris
Links:
my member tank thread:
http://www.talkingreef.com/forums/me...irst-reef.html
Durso FAQ:
External Overflow
Aqua Silencer:
Stockman Aqua-Silencer Overflow Model: Premium Aquatics
