[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [APD] Tank volume and Filter flow rate
Thanks for your splendid explaination. And I will certainly purchase that book from Escobal.
Quoting "S. Hieber" <shieber at yahoo_com>:
> If you don't want to actually time and measure the output
> from a pump (or filter) then as a rule of thumb figure that
> the output is about half the rated output. That's clsoe
> enough, imo, for planted tank purposes. Rated outputs
> usually are for completely unobstructed flow with no static
> head. Filter media, biofilm tht develops in the thubing
> walls and on the impeller and impeller housing -- all thise
> things reduce the real flow.
> Eheim generally gives two specs for filter output -- one
> for the pump head alone and another for the filter with new
> media (but again no tubing or such complications).
> Unfortunately this apparent improvement in accuracy is
> belies by the Eheim techniques -- eheim seems to always
> rate larger canister filters with a higher output than
> smaller ones in the same series even if they use the same
> pump head and have a higher static head do to the larger
> amount of media (the taller canister) the water must flow
> through. The best explanation I ever got from Eheim for how
> they conquered the laws of physics was that they use
> different "tolerances" when rating the filters. Whatever
> that means, it at least means that their measurements for
> different size filters are not comensurable, imo.
> Personally, I'd probably run two 2228s on a 600 liter
> aquarium or else, maybe a 2250. But there's little science
> in the hobby on what you *need* to have as opposed to the
> different kinds of setups that can work. Many folks use
> very little filtration at all, others try to get about 5
> times the tank volume in hourly flow -- which, btw, once
> you do the calculus, equates to a complete turnover of the
> aquarium water 2 or 3 times a day.
> A well planted aquarium is not nearly so fussy about
> filtration as a nonplanted tank -- after all, plants are
> good filters for nitrates and phosphates . . .
> You would probably do fine with just the 2228 and a
> powerhead for added circulation if you find you have some
> stagnant areas in the aquarium. Running two filters gives
> you the expensive advantage of only messing with half your
> in-filter biofilter at a time.
> Since you already have the 2224, you might try running that
> pump on the CO2 reactor. If it's reasonably effective
> reactor, that should be plenty of flow for that purpose.
> Alternatively, you can stick to just one filter but clean
> it more often as it will load and have its output reduced
> more quickly than if you rune two.
> But I'm sure you could have a great tank either way.
> A good source for basic formulas on tank equipment, if you
> are willing to make the simplifying assumptions necessary
> to make the formulas at all practicable, can be found in
> this book:
> _Aquatic Systems Engineering: Devices and How They
> Function_ by Pedro Ramon Escobal, Martin A., Jr. Moe
> You can order it from most bookstores or get it at the
> usual joints like this:
> This covers aquarium water turnover rates, filtration,
> skimmers (for those salties among you), UVs, etc. -- lots
> of basic stuff.
> Good luck, good fun,
> Scott H.
> --- Roger Thomas <sniper at home_net.my> wrote:
> > I have a 5'(L) x 2.5(W) x 2'(H) tank. (650 litres to 700
> > litres volume?) The glass thickness is about 1cm. I have
> > a gravel thickness of 4 inches overall.
> > I have 2 units of Eheim canister filters. These are the
> > 2224, rated at 700 litres per hour (circulation 500
> > litres per hour) and 2228, rated at 1050 litres per hour
> > (circulation 750 litres per hour).
> > (Reference:http://eheim.com/faq.html#question5).
> > Those two filters are housed inside the tank cabinet. The
> > cabinet height is roughly 2 feet.
> > Currently only one filter (2228) is running and the
> > output goes into a CO2 reactor and back to the tank.
> > Somehow I felt that the return is _too_weak.
> > Is there any sort of calculation that I can do to
> > determine whether I need to install the second (2224)
> > filter or perhaps another 2228 ? Please advise.
> S. Hieber
> - - - - - - - -
> Amano Returns
> to the AGA Annual Convention
> Nov 2004 -- Baltimore
> Do you Yahoo!?
> Yahoo! Mail SpamGuard - Read only the mail you want.
> Aquatic-Plants mailing list
> Aquatic-Plants at actwin_com
Sign Up for free Email at http://ureg.home.net.my/
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com