maintaining consistent pump flow?

[scarpenter]

I am having a problem with maintaining flow from my twin return pumps. this is an issue because the water level of my sump changes ...which changes my auto top off's accuracy. I currently have a 120 gallon reef ready tank that uses 2 durso drains and 2 returns. I wonder if it would be better to get one pump that is variable speed and if an apex or other controller could maintain the water level for me with the help of a float switch in the main display?

 

[myram]

So you have one sump with 2 drains going into it, then 2 return pumps?

I think you would have better luck with 1 return pump split into 2 return lines.

Your water level shouldn't be changing that much that fast, only thru evaporation. It sounds like your drains can't keep up with the flow. The display level is probably rising up and then the drains catch up for a minute which puts the water down into the sump, then it happens again..........just a cycle of highs and lows. Each 1" bulkhead is only good for 600gph max, normally less I've found. Have you tried turning down the flow of your return lines to see if that helps?

 

[scarpenter]

yes i have two return lines each with their own pump (each pump is 600 gph). this is not something that happens all the time mind you. just seems especially awful this season change for some reason.

an No I have not tried turning down the flow. I will try that!

 

[scarpenter]

come to think of it...both my gate valves and my drains have a long way to be opened up. but I never open them all the way up because it's so loud with all the air rushing through with the water.

 

[myram]

It's just very odd that your level is fluctuating that much in your sump.

My tank level is rock solid stable, and my sump level is rock solid stable........I could video them and it would like like a still picture. I have my ATO dialed in pretty tight, so it tops off very little but very often.

 

[Jeff210]

I have essentially the same set-up on my 210 and agree that using only a single return pump split into 2 return lines is the way to go (that's how I have mine plumbed).

Like myram suggests, I have found that you have to tweak your return flow rate out of your pump until it equalizes the overflow/drain rate. Although I have a sch 80 ball valve on my return line that I use to regulate the return flow rate, I would use a gate valve if I had it to do over again - more precise and easier to turn.

Like you, I had the same issue with sump levels varying (myram hit the nail on the head with the 'cycle of highs and lows' comment). To remedy this I use my Apex to only turn my ATO (a Tunze osmolater) on 3 times a day (every 8 hours) for a maximum of 9 minutes each time. This replaces the evaporated water without having the ATO kicking on and off all the time which I found contributed to the fluctuating sump level issue.

Bottom line, use a single return pump and do some tweaking until everything equalizes out...

 

[Jeff210]

come to think of it...both my gate valves and my drains have a long way to be opened up. but I never open them all the way up because it's so loud with all the air rushing through with the water.

Do you have your overflow/drain lines into your sump restricted? I would open them all the way if you do...you want as much water to get to your sump as possible. Are your overflows durso's? Mine are and I had a problem with noise with them as well. To fix that I put tubing into the standpipes through the vent hole that I drilled in the top of each. This, however, is a controversial practice as some have suggested that that allows air to get trapped in the standpipe when I shut my return pump down during feed cycles.

There is a thread that I started regarding this here:

http://www.reefcentral.com/forums/showthread.php?t=2456077&goto=newpost

 

[scarpenter]

thanks!!! this gives me a job when I get home

 

[SGT_York]

Highly recommended to upgrade your overflows. Look into the herbie system for a start.

 

[Jeff210]

Highly recommended to upgrade your overflows. Look into the herbie system for a start.

*sigh*

I just finished my 210 build and plumbed it with durso's...

NEXT TIME I will definitely get a tank drilled for herbie AND sched 80 bulkheads...

 

[scarpenter]

so Jeff,

what you're saying is too widen the holes at the top of the durso's ?

https://vimeo.com/111457809

 

[Jeff210]

I would open up your drains so that they are flowing at 100%. If it gets too noisy (as mine did) get some tubing and stick it down through the top of the hole in the top of the durso's (you may have to drill it out to match the outside diameter of the tubing you use). This quiets it down a great deal - but like I said previously and on that other thread I posted - there are those who are not too keen on this practice...

 

[scarpenter]

how long of a tube? as long as the durso standpipe? how long does it stick out of the top?

 

[Jeff210]

I have mine running the full length down to the bulkhead (or maybe an inch shorter). The amount sticking out of the top really doesn't matter (mine is about 8 - 10 inches but I have a 20" tall canopy)...enough that you can grab it and yank it out later if you want to...

I also have a 4" chuck of sound proofing material that I hollowed out in the center on the end of each tube that is sticking out of the top...I built my cabinet and canopy and put sound proof baffling on the inside so I had some extra...helps quiet it a bit more...