flow through the sump

kwirky · #1 05-07-2007, 03:50 AM

I'm confused as to how fast water should be moving through a sump. There are so many factors involved. How much water should flow through it for the skimmer to have stuff to pull out? If that needs to be high, then how about people who use low flow through their sumps to cut down on noise/micro-bubbles?

Anyone with their experiences with slow/fast flowing sumps and what they liked/disliked?

cprowler · #2 05-07-2007, 03:59 AM

I think you want 3 to 5 times the display volume per hour. Check out this link.

http://www.melevsreef.com/what_sump.html

Joe Reefer · #3 05-07-2007, 04:25 AM

I have to agree with Bill, all though I have heard figures higher than that.

I tried for 10+ turnover though a 29 gallon sump, I ended up with 5 baffles to finally stop microbubbles.

SeaHorse_Fanatic · #4 05-07-2007, 05:13 AM

I have just over 3 times flow through my sump. My reasoning for low sump flow is so that the skimmer has more time to skim the water, compared to high sump flow.

Anthony

scumchug · #5 05-07-2007, 07:16 AM

I'm running 12X flow with no noise and no micro bubbles

Delphinus · #6 05-07-2007, 04:18 PM

IMO there's no real advantage to having a high flow through the sump. It's not bad if you can do it, but to me I'd rather look at flow within the tank with things like wavemakers, powerheads, waveboxes, Tunzes, closed loops, etc. etc., and just have the sump as a place to run the skimmer, heater and any other filters or equipment (phosphate reactors, carbon, etc.)

Plus, it's just easier to keep the microbubbles and noise in check. For example I have somewhere around 9-10x volume turnover on my 115g cube tank right now and it sounds like a whitewater rafting river in the sump, and if I take out the filter sock, the tank is literally white with microbubbles. A longer sump would work but I'm restricted to what can fit in the stand so I'm stuck with about 28". I can't put more baffles in and still hope to fit my skimmer.

I think I have about 8x volume turnover on my 75g but because I'm using a 48" sump I don't have the microbubble problem on that tank. It's just sheer luck though, had the sump been any shorter there would have been a microbubble problem. It too has a bit of a whitewater river rapids thing going on. Between these two tanks my basement sounds like Takakkaw Falls. I'm never running sumps with over 5x turnover on any tank I set up next.

andsoitgoes · #7 05-07-2007, 04:48 PM

I agree with Tony - With the sump, you want to have the water in there as long as possible for heating, skimming, etc.

I've got about 1.5x turnover if not less - s'all I need the system for it to skim, heat, sterilizer and push through carbon. It's in the bedroom so it's quiet, no problems, makes me a happy camper

Every now and then it sounds like a big monster is sucking dry the bottom of a slurpee container, but that's easily fixable, sometimes - usually without TOO much swearing and adjusting of chaeto :P

digital-audiophile · #8 05-07-2007, 04:52 PM

I have around 3 times turnover per hour with my sump. This is becuase I had to trottle back my return pump as I only have one 1" drain on my 90 and any more flow back into the tank causes a flood

The nice slow turnover works well as I have zero microbubles back into the tank.

danny zubot · #9 05-07-2007, 06:57 PM

Is the turn over rate determined by the tank size or the sump size? My tank at 65 gallons means I have almost 14x turnover, but my sump at 25 gallons gives me a 36x turnover rate. (Mag 9.5 return)

Delphinus · #10 05-07-2007, 07:06 PM

I look at it as tank volume plus sump volume (or.. well .. "volume of water in sump" since a sump isn't run full). So that's more like 10x turnover per hour in your case Danny, although it's probably more like 8-9 times since the sump return is likely putting out less than 900gph at 4'-5' of head pressure.