water turn over and pump size

[b-gin-86]

Hi I am setting up my 92 gallon bow front. it is five feet tall and I am switching my pump. I am installing a hydor 740. it has a max head 7.5 feet. Now that I have replaced my old pump with the hydor I don't think it has enough flow. How many times should I be turning over my water every hour? I changed my pump because my old pump was 100 watts and the hydor is 40 watts and the water flow was only a little more on the other pump. Any suggestions? thanks

 

[b-gin-86]

I have a thirty gallon sump with one intake and a 100 micron sock. some examples would be great also

 

[3Twinklets]

Pump max head estimates are usually estimated by companies on the pump operating when new. I would have gone up at least one size maybe 2.
Maximum turn over of tank water volume is hard to express for me. I just know by watching the pump, if it is moving enough water. Also if you have a constant level sump, you would know by the water level in that.

 

[mfinn]

If it were me I would use a pump that gives you about 5x the tank volume through the sump.
Something in the 450 gph to 500 gph after headloss.

 

[b-gin-86]

i replaced the new pump with an older more powerful pump. I just installed a loc-line check valve. I don't know if the check valve slowed the flow down much but it seemed to. My old pump was creating to much water turbulence. I just installed two kessils a350w's and they create a lot of shimmer. With the flow I had it was actually to much shimmer.

 

[AZDesertRat]

You should never use check valves on a saltwater system, they are a false sense of security and can and will fail. If the return and sump are designed properly there is absolutely no need for check valves or drilled holes.

I like to see around 5x the display volume for a return pump after headloss provided the sump is large enough to handle the velocity without microbubble issues. It is cheaper and more efficient to make up the remaining flow with powerheads or propeller pumps at a few watts apiece.

 

[CastAway]

In my own research, I think the modern day average is 3x turnover through the sump, and 10x turnover in the display. I think it can vary depending on what's going on in the sump, i.e. refugium or live rock, compared to what's going on in the display, i.e. sand bed & live rock. If all your biological surface area is in the display, it may serve little purpose to force a lot of turnover through the sump. Of course if you're relying upon the main circulation pump to provide the turbulence in the display, that's another thing.....

 

[Av8Bluewater]

In my own research, I think the modern day average is 3x turnover through the sump, and 10x turnover in the display. I think it can vary depending on what's going on in the sump, i.e. refugium or live rock, compared to what's going on in the display, i.e. sand bed & live rock. If all your biological surface area is in the display, it may serve little purpose to force a lot of turnover through the sump. Of course if you're relying upon the main circulation pump to provide the turbulence in the display, that's another thing.....

I'm not following you. Do you mean 3X through the Refugium and 10 from the return coming out up top?
Usually when People talk about turnover in the display they are talking about total flow including powerheads. Usually a lot more than 10X. SPS systems you need 50X Plus.

 

[tigerdragon]

I went with 10x through sump and in the range of 20-30x in tank. When fig head loss all valves, elbows, 45's height, and line size come into play with head loss

 

[dantimdad68]

I have always used 3x through the sump and between 10x an 20x in the display depending on what was being housed in the display.

 

[RacingTiger03]

Yeah, I'm a bit lost on this one.. I've always shot for 50-80x turnover on display water volume total. Granted I've never done a sumped setup either. I run a koralia 850 and koralia evo 1150GPH powerhead in my 30 + a skimmer with a rio 1200 (200GPH head rating IIRC.. maybe 30-50GPH output, I don't even count it) and still would like a little more flow, eventually I'll replace my 850 with another 1150. That's about 75x turnover when you factor in actual gallons of water in the tank

 

[tigerdragon]

In my 90 mixed i run a mag18 rtrn with head loss fig it to be around 900-1000, in tank i run 2rw15's say set around 40-50% pwr, koralia 1500 and seio 1500 blowing across back. My sps love it and lps and sfties doing good to

 

[evolved]

Bear in mind, there's two different flow rates being discussed here.

Flow rate through the sump (only dependent on the return pump)
Turnover rate in the DT (dependent on the return pump, but primarily dependent on powerheads, wavemakers, etc)


The return pump should be sized to provide what flow rate through the sump you desire, which is a matter of the equipment in the sump, refugium, etc. Too much flow and your equipment can't work optimally; too little and detritus will settle elsewhere in the system (and not in the sump).

The turnover rate in the DT should be set by the type of coral you wish to keep. Softies need the least, LPS a bit more, and SPS need the most. It is most efficient to get the desired turnover rate in the DT with powerheads (as opposed to a larger return pump).

 

[tigerdragon]

Agreed. Being as i have mixed i went to the higher

 

[alohadood]

Isntt he turn over in the sump just an aggregate of what the turnover of the DT is...?

I go for between 3-5x GPH of the DT volume, I also Skim very wet and prefer a slow flow through the system to really help churn the system and give the biological and mechanical filtration methods a chance to catch all they can.

 

[tigerdragon]

Kinda depends on what you run for filtration i run a bm nac9 which is rated for up to 500g and off my rtn i run an ats and a carbon reactor. I pulled my socks so far everything doing good p04 according to my hanna tester is 0, and trates show very low. I also skim to dry side pull really dark skim

 

[Streetcred]

I've always worked on the premise of 3x - 5x/hr of the display net volume running through the sump / refugium. Lower end if the sump / refugium is smaller rather than larger. I've recently given this some thought ... in years gone by we had beckett skimmers that required strong water flow to operate effectively; that was when we recommended 3x - 5x flow rates. Nowadays our needlewheel skimmers run more effectively at 1 - 1.5x/hr display volume ... refugiums don't need fast water flow, sumps are more effective at settling out solids at lower flow rates, skimmers don't need it ... so why do we need anything beyond say 3x/hr net display volume?