What is the optimum flow rate (GPH) for nano tanks

[halibutk]

I posted a generic question because im looking for what the optimum GPH flow rate for a 20 gallon nano is that im setting up in my office (feeding through a ten gallon refugium).

 

Thought by making it generic we could feed GPH stats on other nano tank sizes too.

 

Also what pump would I use to feed the water back into the tank from the ten gallon refugium/sump. Its got about 18" head with about 36 inches of pipe to the tank(head i think is defined as elevation change between pump and outlet of water....correct me if Im wrong).

 

Im looking to start buying supplies for my new office nano soon (meaning new pump, lights, etc)...They are remodeling my office in the next two weeks which gave me the excuse to take down the freshwater tank I have had in my office for the past 2 years and spend the money setting up a new nano at the office.

 

Also on a bit of a side note. Running a ten gallon refugium (DSB) with possibly mangroves (havent decided yet...need to hear more pros/cons and difficulty of care first) would I still want a skimmer.

[tinyreef]

the flow kind of depends on the aquascape and livestock. some setups need more flow rates than others so yours is a loaded question. you can start around 10x volume per hour as a catchall.

 

guestimating i would think you'd need a mag 5 or more from that info you provided. that could be way off base tho.

 

you also need to calculate the right angles for the return pumps. better to oversize than undersize ime. if it's too much you can always swap the return outlet larger (e.g. 1" return to 1-1/2" return or even a tee).

[halibutk]

Thanks for the response.

 

Maybe to clear things up I need a bit more info. Anybody use one of these hang-on-back overflows that are rated at 300 gph and do they really run that much or is their flow more or less.

 

Sorry if these seem like stupid simple questions, I just cant think very mechanically?

 

Can you clock overflows down by attaching a ball valve to the pipe leading from the tank to the refugium, or will you lose suction? If you can then I could pretty much regulate what my flow is right. But sounds like I would want 200-250 gph flow for 10-12x per hour.

 

lets say they run at 250gph then i would need a pump that could handle 250 gph back into tank, right.

 

Is that flow way to much for a refugium (meaning that a ten gallon refugium/sump would have the water from the tank cycled through it about 12 times a hour.

[BigReefer]

another reason i chose the eclipse system (even though people dislike them!) The internal filter system pumps out 150gph which gives more then enough flow for a 12 Gallon! I dont know much about powerheads but good luck with your search!

[ChrisIsBored]

FWIW, I'm using a penguin-mini HOB + another 200GPH powerhead in my 7G bowfront and to me I think I could still use another 100GPH or so...

 

Flow = Good

[MKramer]

[edit for typo]

 

An overflow is entirely self-regulated. As long as you flow under its max flowrate, it'll function correctly. Although I have seen poorly-designed (usually DIY) hang-on-back overflow boxes that break siphon if the flow gets too low. This shouldn't be a problem with anything reasonably well designed.

 

If you want to throttle the water turnover rate in your tank, you can use a ball valve on the output of the pump.

[MKramer]

Here's an animated gif of how a HOB Overflow box works, and maintains siphon even when there is NO water flow entering the tank.

 

http://reefkeeping.com/issues/2003-01/gt/i...mic-labeled.gif

 

The animation was done by Greg Taylor and appeared in the January issue of ReefKeeping:

 

http://reefkeeping.com/issues/2003-01/gt/index.htm

[BigReefer]

hey, thanks for that link Kramer

[halibutk]

Man its just one of those things that I just wasnt getting till I saw that animation. Thanks (even though I has seen the animation before It took me two weeks to understand it and see it again)

 

I get it thanks to all that replied I feel safe in my current design for my nano and I can resume setting it up.

[Pikelet]

10 x the gallonage of the tank is an old rule of thumb to ensure that the filter saw enough water. I think that is a little on the light side for many reef tanks. I have about 200gph split between a Whisper power filter(no inserts) and a small powerhead. At 20x gallonage that does not give quality random flow in the tank in my opinion so take the old rule of thumb with a grain of salt. Powerheads do a much better job of circulation. Power filters are a compromise allowing you to use filter inserts when necessary.