overflow question

[stkitts]

I have a 180gal with a 100gal sump. I have the bottom drilled and 2 overflow boxes dumping through the bottom to my basement sump. I have some eggcrate in the bottom of the overflow boxes with some filter on the top to reduce the noise. My LFS reccomended to run without the filters and setting my return valves so that the water stays at the half way level in the overflow boxes. Is this safe? what are the chances of them overflowing? I have hardwood floors and this would be a disaster.

[Reefmedic79]

I would remove the filter as well as they tend to get clogged and lower the efficiency of the overflows in time. There is no chance of the boxes overflowing, unless your return pump is over powered and sending more water to the tank than what can be drained.

[stkitts]

The reccomendation was to restrict the return lines (reduce the return valves) so that the overflow boxes are kept half full. I was told that they would remain at this level, not overflow and also be more efficient. My question, is this correct?http://reefcentral.com/gallery/data/1/119961DSC00036.jpg

[ahenson]

The water level in your overflows is determined by the height of your plumbing drain pipe. What size pipe are your drains? How many do you have? And what are you using for a return pump?
Is this your only circulation or do you have powerheads in the tank?

[stkitts]

I have two 1 1/2" drains and they are all I have. My pump pumps into two double powerheads.

[ahenson]

I would open your pump back up. 1 1/2 drains can handle a lot

[rick s]

Are you saying you have valves on your drains? On the pipes that leave the overflow boxes and go to the sump?

[stkitts]

Yes. I have valves on both retuns and both pipes to the powerheads.

[theatrus]

Never close down the valves on the drain pipe :) You want that to flow as openly as possible.

[rick s]

I would never use valves on the drains. If you try to “balance” the water level in your overflows by using those valves, you don’t leave yourself any leeway for when something changes.

From what you are posting, you could have either or both of these water “noises.”

1. Noise from the water that falls from your tank into the overflow box. If the water is falling, it is splashing. If it is splashing, it probably is making noise. From what I see in your picture, your overflow boxes are empty. The water is falling a good distance and making noise. Instead of closing your valves: Remove your eggcrate and filter sponge, and install a piece of pipe into your existing drain pipe. You want to “extend” your drain pipe up a few inches so water will collect in the overflow boxes and then spill over into the drain pipe (extension). You should be able to make a fairly water tight seal simply by using a different diameter pipe, or a coupling, etc. That piece of pipe should not be too high. You want some “fall” into the overflow box so it “pulls” surface water through the combs.

2. Noise from the water falling down the pipes into your basement sump. PVC will exaggerate noise. If you are using straight PVC pipes, water is falling a great distance and then crashing into the water in your sump. There are quite a few ways to reduce this noise.
.....1. If you can angle the pipes heading to your sump the water will “slide” down the pipes instead of randomly crashing into the water below.
.....2. This worked for me: I use a 3' flexible pool hose from my tank drain. It slowly goes from vertical to horizontal. The water gradually collects and slows. I have no “crashing.” I played with it at various “angles of decent” and was able to get it perfectly silent. You might want to try the flexible hose where the water enters your sump.

Hope this helps.

[stkitts]

http://reefcentral.com/gallery/data/500/119961DSC00033.jpg
This is the setup under my tank. The dark grey (horizontal) pipes are the return lines from the overflow boxes. There are pipes hiding behind the 2x4s in this picture that go up to the boxes. The boxes are not installed in this photo. The light grey (vertical) are from pump to powerheads. The noise is more of a suction. I am interested in trying a pipe that creates a higher level in the overflow boxes. I am also having trouble with the slots in the boxes getting clogged with slime and raising the tank level. Any suggestions?

[Shagsbeard]

Try placing a 90 deg bend or a T fitting over each drain loosely (not glued). Find the largest that will fit in the drain. The suction will keep the fitting in place. If you want the water deeper, simply add some pipe length to the fitting so it sits above the drain.

This will cut down on a suction noise as the water will have to bend it's path as it enters the drain. If it doesn't work, you're not out anything.

[ahenson]

Do some research for a durso or stockman silencer. That is the drain plumbing you need. That will eliminate the noise. Restricting a drain is horrible advice. LFS advice usually gets redone in the end unless you find someone special who knows rather than is an "expert"

[stkitts]

I have just returned from my LFS with a plan. He had my exact overflow boxes and I found that my return pipes are 1 ½”. I tried to do the durso silencer but did not have room for all the plumbing in 1 ½”. I am going with a “T” and a cap with a vent screwed into my box bottom. I won’t have a turn down fitting (“L”) as I don’t have the room. I will let you know how I make out. Thanks for all the great advice.

[ahenson]

The stockman silencer will work with less room.

[stkitts]

Does it come 1 1/2 "?

[MCary]

You can make one or buy one. Its basically a large endcap placed over a smaller pipe with some strategically placed holes and air vents.

http://home.nc.rr.com/stockmanreef/interest.htm

Mike

[ahenson]

premiumaquatics.com sells them as does Ken Stockman at least he used to.