Need suggestions--Challenge with return volume

[N8ster]

OK, I have been researching everything, and I thought I finally had everything crammed under my stand just the way I wanted, and now I have a small problem.

When I turn on the return pump and the skimmer, the water level drops too much in my return chamber, and I get bubbles going up to the main tank. The pump also gets a little louder, because it is not fully submerged. I figured it would be fine--it is a pretty big container, but it drops 4 inches or so.

Any suggestions?
Bigger Container--would obviously work, but I would hope to avoid this--I would rather not completely rework all of the plumbing, buy another container, etc.
Reduce size of return line--Currently using a 1.25" return. Dropping down to 1" would help a tiny amount.
Use one overflow box instead of 2--Might solve the problem, but I would prefer to have both overflows running.

Are there any other tricks I should consider?

90 gallon, Mag7 return pump, DIY sump, RDSB--plumbed, but no water flowing through it yet, DIY stand. The empty space on the left will hold a container for auto-topoff.

 

[Shagsbeard]

How about simply adding more water?

 

[ambaratur]

Shagsbeard has a good suggestion.

How many gallons does your return section hold total?

 

[eckrynock]

Not enough water in the display tank/sump to begin with. Do what shags said.

 

[N8ster]

I start with the return section 1/2" from overflowing, and then turn everything on. The water level drops too much. If I add more water, it will overflow if the power goes off.

I don't know the exact size of the return section. I used a big tub, and cut it to fit in the space. I could raise the sump up an inch or two, but I would like to know if there are any ways I could avoid this.

 

[ericwebster]

Maybe add an underflow to your main baffle system. Without a picture its hard to visualize. May create more problems.

The water level in my sump is over the baffles when everythings off and I have lots of top off water in the tank. But its not overflowing the sump.

 

[JeffersonReef]

IMHO, it sounds like your return pump is pumping up more water than your overflow can handle. That is the only reason I can think of why the water level in ur sump would drop. How many GPH is ur overflow rated for, and how many GPH is ur return pump rated for (taking into account head-loss)? Also, I agree that a pic would help.

-TJ

 

[N8ster]

I will try linking in the photo again--since the previous one isn't working.

<img style="FLOAT: left; MARGIN: 0px 10px 10px 0px; CURSOR: hand" alt="" src="http://photos1.blogger.com/blogger/2240/1111/320/P9280003.jpg" border="0" />

The overflows can handle the flow, otherwise the main tank would overflow, right?

Are there any tricks to reduce the volume of water that gets held up in the pipes? Then the water in the return wouldn't drop as much.

The white tank on the bottom is the return. The section between the skimmer and the fuge drains straight down into the return.

 

[N8ster]

http://photos1.blogger.com/blogger/2240/1111/1600/P9280003.jpg

 

[JeffersonReef]

Maybe I am misunderstanding.... but that doesnt seem to make sense. When you say your "return area", I assume you mean the area where your return pump is located, correct? If so, and if this is where the water level is getting too low, and yet your display tank is not overflowing... then like someone said before, you need to simply add more water to the return area/sump. It wont overflow. Whatever gets pumped up will get overflowed back down, as long as the overflow can handle the amt of water that is pumped up. In a correct setup, you dont have to worry about the water level in ur display. It will stay constant, and is dictated by your overflow box/ location. The water level that needs to be adjusted frequently (due to evaporation or lack of enough water in ur case) is what is in ur sump. Try adding a few gallons, and see what happens. The display tank should stay the same, but the water level in the sum should rise. As far as worrying about ur tank overflowing in the event of a power outage or something, that is dictated by how deep your overflow is located in ur tank, as well as how deep your return line(s) is in the tank. If you plan this properly, and maintain your water level in ur sump accordingly, then if there is a power failure, the water shouldnt overflow out of ur sump. I keep mine just a bit over half full.

-TJ

 

[Brianr0131]

You could add more water. That's really what you need to do. Although, from what you're saying you're close to overflow now in case of power outage so I guess that's out.

You could add a ball valve after the return pump and choke it down a little, that should help.

Whatever you do don't take one of the overflows out that could be a really bad thing. If your overflow doesn't keep up with your pump you could wake up to a really wet floor. This can happen over time as well if it is only off a small amount and it could catch you by surprise so if anything you want MORE overflow capacity than return GPH.

 

[N8ster]

Thanks for all your comments.

I think I have figured out the problem--the siphon break on my return is too low in the water. This is causing too much water to drain back down from the main tank when I turn off the pump. I will raise the sipon break, which will eliminate the large volume of water coming back down into the return tank.