Turnover confusion

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Snotman

Aquarium Advice Apprentice
Joined
Dec 27, 2006
Messages
47
Im sure this has been covered many times but the posts I have found dont answer exactly what I need to hear :)

Ive just set up a 6ftx2ftx2ft with 40g sump. Works out abot 18g in total.

I cannot fully open my Aqua medic OR 6500 return pump as the overflow cannot cope and the level rises. Plus the Bio balls in the weir sound like a thunder storm. Therefore its throttled back a little with a ballvalve on the intake(not too much).

I hear people refer to required turnovers of around 15-20x water volume per hour for reefs. My return pump when fully open would turnover 1500 gals an hour. Not even 10 times my tank volume through the sump. I have a huge powerhead turnover in the tank, of around 1650 g/hour. This does not include the myriad of powerheads running assorted reactors etc.

Do I add both turnover figures together or is the turnover rate of the tank, just the rate through the sump?
 
The GPH from the return and the GPH from the PH are calculated together. Only thing you wouldn't factor in most of the time is the GPH of a skimmer pump unless it's HOB and even then I personally don't count that since the flow is usually fairly dispersed.

I assume you meant 180 gal and not 18 gal. Since your Aqua medic pump does 1625 gph at 0 feet it's probably close to 1200 gph with a 4ft head and I assume since you have to restrict it you are probably getting close to 800 GPH from the pump.

The 800 plus the 1650 GPH for your 180 gal tank works out to about 13.6 turnover. That's not bad but a little more flow either using a closed loop or additional/more powerful PH will probably be needed depending on the types of PH you are using and corals you plan to stock.

What brand/model of PH are you using?
 
If you haven't already I suggest looking at the Tunze Nano Streams or the Hydor Koralias, they are excellent PHs for any size tank moving anywhere from 400-1200gph and only using 7-13watts of power. I have a Nano Stream on my tank (660gph) and am adding another one along with a Koralia at 400gph. My tank is only 72 and that is a lot of flow but my corals love the extra water movement. One nice thing about these pumps is the flow they create is gentle and wide.

Do a search for Nano Stream or Koralia on google. I think you will be pleased!
 
Tec your correct sorry for the typo!

After a measure of the tank and recalculation turns out its a 160 gal (US) as I forgot about the angled corners and the weir box.

I currently have an OR2500 running a 5 port closed loop around the base of the tank, buried in the sand (well mostly :D ).

I have:
2x Korelia 4, 1 at each side of the tank (low, slightly upward pointing)
1x seio superflow 2600-10k lph (central backwall facing front central)
1 OR6500 return from sump. ever so slightly crancked back prob acheiving about 4000 lph at 4ft.
3x 1000lph assorted PH running various reactors (phos etc)

so lph without reactors/skimmer etc=
2500
4600
4600
10000
4000
25700
Thats 6425 g/h in your currency (Im a Brit). I make that 40x turn over 8O
Am I missing something here????


I love the korelia's. great power to movement ratio. 2 complaints: noisy start up (clicky impeller) and I use an Aqua Medic wave unit so I hear it a lot. And in the UK the 2 and 3 models have all been recalled as they are self distructing in tanks etc. Bit of a worry for 1 and 4 owners, but no probs yet.
 
40x turnover using wide stream ph like the Hydor Koralias/Seio isn't going to be an issue with most corals since it doesn't cause heavy direct currents. I have Seio pumps as well with about 38 times turnover and I'd describe the flow for corals as medium in most parts of the tank.

You will have to creatively place lower flow corals (Mushrooms, Brains, Sun Coral, ect..) though to avoid getting blown around too much which can damage them.

Also since you have the wave timer I assume 2+ ph are cycling on/off so the true GPH is slightly less.
 
I agree, the SEIOs are great at adding a dispersed flow, the Hydors are great as well. On a side note, I have seen a snail crawl across the Hydor and do his thing (munching algae) and didn't get stuck or sucked in.
 
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