alternating gyres

[monotreme_man]

i have seen a few references (especially in the large tank builds)
to people who have implemented gyres for tank flow.

has anyone implemented alternating gyres, that is,
where periodically, the gyres change direction
(or i guess more accurately, transition to a different gyre)?
or know of anything written up about this?

 

[Fragman2]

Yes, many of us have been doing this for years. I recently attended a talk by Jake Adams on this subject. He has implemented and studied alternating gyers on small tanks (40gal.) up to a 1200 gal. tank. The 1200 gal. tank wa especially impressive as there was no closed loop or any other current other than the return from the sump. Four Vortec pumps alternating with another four Vortec pumps create a clockwise then counterclockwise gyre that alternates on a cycle of approximately 10 to 15 minutes. I would do a search starting on this site for Jake Adams and see what you find.

 

[ctenophors rule]

awesome idea, they have a gyre running at macarthur beach state park in the turtle tank, but it doesn't reverse.

i am wondering though, will 15 minutes one way 15 minutes another realy benefit coral?

i am assuming that you guys want to use this for corals to prevent latent flow, but wont the corals develope a memory to the pattern eventualy and have the same problem?

thanks, sorry if it is a stupid question, tommy.

 

[Atomikk]

Call me crazy, but how is this method any better than what we currently have for random flow? How is a gyre supposed to be great on a 40gal tank? Sand blowing around everywhere, clogging any equipment that you may have (or just going into your overflow)

 

[ctenophors rule]

well, if the gyre were weak enough it wouldn;t be blowing sand around, just clumping it in middle, maybe.

i think that the wave makers and those spinning power heads, not the oscilators, but the ones on the dj turn table motors, are better than the gyre, but the gyre could be set up in a less expensive manor.

if you set up the flow correctly and puto ne pump on a quick timer, you can get just as much variability in flow as with the best wave makers

 

[monotreme_man]

according to mr gyre (jake adams), the issue is to get water velocity.
the gyre is just the most efficient way to do that, but not the only way.

my problem is i don't have enough experience to judge how important this is.
jake's talks seem compelling; he actually measures how effective
water velocity is by measuring how much respiration (in the coral) takes
place. but obviously there are many other factors.

for my tank (84in), i get about 20in/s in my gyre fed by 3 modded maxijets
(at about $100 total). the accepted wisdom is that i need something
like 2-3 vortech mpw40s ($700-$1000). that is a bunch of difference.

i'm quite willing to go do teh right thing, which in aussie, is to suck
it and see. i just wanted to get the benefit of prior wisdom, first.