closed loop downfalls?

[shabreeson]

I was reading a previous TOTM and was wondering if a closed loop would suck up fish on the intake, and if not then why?

http://www.reefkeeping.com/issues/2008-08/totm/index.php

also are there other problems with closed loops?

[Willi]

Usually with a closed loop you divide the intake several times. Ie.. I have a Reeflo snapper with a 1.5" intake and that is divided into (2) 1.5" intakes under the tank, once in the tank each 1.5" intake is then tee'd and becomes (4) 1.5" intakes. The result is each 1.5" intake in the tank only representing 25% of intake suction. From here you can add screening, suction basket, etc and healthy fish, inverts can easily keep from getting sucked in.

[Fiziksgeek]

A closed loop is certainly capable of sucking up a fish. But more likely, things like snails or anenomes that get too close. Fish are generally strong enough to swim out of the suction. Remember, the intakes of a closed loop must have some sort of strainers on them. A sick or injured fish is definitely at risk though. And thing dont generally get sucked up into the pump, they just get stuck to the strainers. Not really any less danger than a power head though. Why do you think they sell those foam covers for vortechs??


There are a couple main disadvantages to closed loops.

1. Lot of plumbing which takes up space and could be a source of leaks.

2. Not as efficient as power heads. (high operating costs)

And of course the advantages are

1. easy to customize the flow with split returns and the use of things like locline.

2. easier to hide

3. Lower initial set up costs (most of the time)

Most of the time it really comes down to personal preference...