Archivarium 2004

[robbyrob]

Are powerheads really needed? I mean can I get away with the water flow provided by my filter? Just curious cause I see a lot of peeps set-up include powerheads but the guy at LFS said I really didn't need one, but then again he also said to cycle with 2 clowns so I don't know is creadability is not too high with me right now!!

Rob

[SLACkra]

depends on the power of your filter and the size of your tank. I would recomend that the entire tanks volume should be pumped around at least 6 times an hour. so if you have a 20 gallon tank thats 20x6=120gph of filtration or water movement.

andrew
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32g planted community
7.5g Nano Reef
1 four legged wonder napper
2 winged demons

[KDodds]

6x? For a marine tank? Most, myself included, are recommending 10x, minimum, for a FO or FOWLR. For a reef, depending, the min would be more like 20x. You can't really count the flow from Power Filter or Canister Filters. More often then not, their rated flows are exagerrated (run empty) and the ouotput is too diffuse to give enough velocity to move enough water. PHs are an option, but many people use single return pumps in their sumps and/or manifolds and/or closed loops to save in-tank space.
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Kieron Dodds
Inside Aquatics
www.insideaquatics.com

[SLACkra]

actually its 10-20 X tank volume of water movement if you have sps corals. some corals don't apreciate a lot of water movement.

If you can try to get a flow ajustable power head that makes it around 10 X tank volume of water movement. If its too much water movement for you lower it.

my 2 cents
_________________
32g planted community
7.5g Nano Reef
1 four legged wonder napper
2 winged demons

[KDodds]

No, actually it's more like this:

10x for a FO/FOWLR. Keep in mind that a 600gph pH is going to produce too much velocity in a 60g tank, so you'd want to split it into two 300gph PHs. Chaotic movement is important too, but mostly only in reefs.

For a corallimorph/soft/low current LPS tank, you MIGHT be okay with 10x, but 20x would be better. Using the example above, 4 300gph PHs would probably be a reasonable set-up.

For mid to high current LPS and some SPS, a MINIMUM turnover of 20x is recommended.

For mid to high current SPS, 20x remains the MINIMUM, but 30-40x is preferred.

Even so, you'll find that some softs not only take, but prefer higher currents (like Sarco, Sinularia). Other will adapt. Low current species in a high current tank can be accomodated by planning certain areas specifically for that purpose. It's pretty much impossible to provide too much current as long as you maintain a velocity of not much more than 4fps from any one point and most corals prefer a good deal of chaotic movement that will not be attainable from a single source, let alone one pumping at 6x. For those interested in verifying this, I would suggest you ask over on Reef Central.
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Kieron Dodds
Inside Aquatics
www.insideaquatics.com

[SLACkra]

I stand corrected. however it was personally recomended to my by a seller of metal halide lighting and keeper of sps coral that 10-20 was recomended for sps.

andrew
_________________
32g planted community
7.5g Nano Reef
1 four legged wonder napper
2 winged demons

[drbdc]

On SPS tanks people are getting in the neighborhood of 40-50X turnover. I have 30 right now and am far from happy. I have some large seio's on order that will give me around 50X in the seio's and 10 on the main sump/refuge exchange. I'd love to get the tunze's but that's 800 bucks. Ahhhh, later. My wife would kill me. My dual mh's just arrived UPS yesterday and I've mentioned how expensive the tunze's are to her so she'd know right away and just shoot me.

You can't get good turnover with a typical powerhead though due to the small high velocity output. You'd beat up whatever is in front. You want a strong laminar flow from a closed loop with multiple outlets or another option is seio's and tunze's. MJ's are good but you really have to be careful where you aim them. LPS and other softes should still have 20X turnover. With a fish only tank you can get away with less flow but your fish really need a current to swim with unless you keep seahorses and only a handful of others.

Reefcentral is probably your best online site for reefkeeping.