Flow Control Help

JCOLE · Jan 31, 2019

Hey everyone! A little frustrated tonight. Cannot figure out flow stability on my new fuge to sump and its driving me crazy. I have a 55 gallon NON-DRILLED tank. I recently plumbed my sump into my garage two weeks ago. Originally I created a syphon for a drain and had a 2450gph pump return to the tank. I was having an issue then as well because sometimes the intake syphon would suck more than the return pump and it was a nightmare keeping them consistent for more than an hour or two. I broke down and bought an Eshopps overflow boxes. That fixed that issue and honestly once dialed in is pretty awesome.

I have a 20 gallon sump I made myself. Everything is running great and over the weekend decided to make another 20 gallon sump for my new refugium and to move my skimmer over. I piped everyone in created the sump over the last couple days. Finally fired everything up tonight and now I am having the same problem with the refugium to sump flow.

See pictures. I have a drain that goes into the sump, then flows to the end of the 20 gallon to the return pump, from there it splits and goes back to the tank and to the new 20 gallon refugium I installed. From there it flows from a 1450gph pump back to the sump.

I have my ATO line in my sump which stays level with the just the drain and return in the sump. Once I get everything on for the sump and refugium then the line drops an inch, I close the input to the refugium some to slow flow and then it rises back up, however it will go way over the line and keep climbing. So then I close the return to the sump a little bit then it constantly drops,l. It does this over and over and never equalizes. If it does then it is only for a couple minutes.

Is there anything I can do or change to correct this.

Also by the way. Excuse the messy wires, etc. Just had everything installed and in the process of organizing everything.

ndrwater · Feb 1, 2019

Part of the problem are the ball valves. They just aren't fine enough adjustment wise to sometimes become an issue. Although it'd be a pain, look into "gate" valves. They are much more precise and allow for finer adjustments.

goatcorals · Feb 1, 2019

I don’t think you’ll ever perfectly align the two pumps. Even if you do, performance changes over time will ensure they will not remain in alignment. Consider raising the refugium to create an overflow back to the sump rather than pumping back to the sump. When you use an overflow, this insures the “fuge” return will never outrun the supply because they are essentially the same volume of flow, input and output of the “fuge”.

This would be easiest to accomplish if you drilled the fuge tank.

JCOLE · Feb 1, 2019

Humphrey said:
I don’t think you’ll ever perfectly align the two pumps. Even if you do, performance changes over time will ensure they will not remain in alignment. Consider raising the refugium to create an overflow back to the sump rather than pumping back to the sump. When you use an overflow, this insures the “fuge” return will never outrun the supply because they are essentially the same volume of flow, input and output of the “fuge”.

This would be easiest to accomplish if you drilled the fuge tank.

That is what I was thinking last night. Staring at all my pipe work and thinking..."man I messed up!" Honestly, I was thinking of just taking my sump out and moving my fuge over to replace my sump. I designed my sump without thinking to put the skimmer in the first chamber. This allows unstable water levels due to evaporation, etc. My new fuge has a spot in the first chamber for the skimmer, then Chaeto, etc in the 2nd chamber. I was just looking forward to using the 2nd chamber in my sump to host mangroves....

JCOLE · Feb 1, 2019

I am going to work on building a higher stand this weekend and make one of these overflows to see how it works. What do you think?

goatcorals · Feb 1, 2019

h2oh2o said:
I am going to work on building a higher stand this weekend and make one of these overflows to see how it works. What do you think?

Sorry, I think it would work but I’ve never used one. Perhaps someone will chime in. I like the mangroves idea!

Based on your plumbing results, I’m sure you could successfully drill the tank. Lots of internet videos showing how. You wouldn’t even have to adjust the stand potentially if you run higher water levels in the fuge. If you drill the tank above the level of the sump, allow flow through Skimmer chamber so entire fuge/skimmer tank is at the higher water level, put the Skimmer on an egg crate stand at desired level, enabling consistent level in the Skimmer area and a relatively high fuge volume? The only fluctuating level would be in the return section of the sump I think. If you don’t have an auto top off this might mean lots of manual top off.

Same could be accomplished with the overflow you showed I’d guess if you are a “no way I’m drilling the tank”, but you would likely have to raise the fuge i’d think. Either way level in the fuge has to be higher than the sump... a little hard to tell where the levels are enabled.

Also one more word of warning. In the “sump is the lowest point” solution, The sump has to hold all the water when you turn off the single return.