View Full Version : Making a Gyre with a simple closed loop 7 ft tank

05/16/2017, 07:04 AM
I am close to rebooting my 300 gallon tank. After 12 years, the only thing I hate more than scraping the back wall of the tank is maintaining and replacing power heads.

I am contemplating a super simple closed loop. The goal would be to create a continuous gyre - similar to what I get now with my maxspects.

I would have one or two 1.5 inch drains on the right side of the tank. I would put a 1.5 inch return pipe at the top - also on the right, with three or four eductors blowing across the top of the tank from right to left. Thus, creating a continuous counter-clockwise gyre. All this would be hidden in rockwork.

I would use reeflo manta ray. Assuming 15 feet of head pressure from the eductors, this would draw 4,500 gph into the intakes. With accelerated flow at the eductors (4x flow), the circulation would be up to 18,000 gph (60 x turnover), which I could dial down with a single valve at the pump - with a target of around 30x.

FYI - I'm also going Bare Bottom and covering three sides of the tank with rock - to cut maintenance.

Comments??? Advice??

01/29/2018, 04:37 PM
Wondering if you ever did this set up using a CL to create a gyre? I'm in the planning stages for a 300g and contemplating something that has an output on one end and intake on the other. I had thought about a horizontal pipe with a long slit along the length to evenly flow close to the surface.

01/30/2018, 02:08 PM
Not yet! Wife says a new fish tank is not a priority right now and we have to remodel the attic first. You know the drill. The trick is to make sure the outflow has the energy to get across the tank before it comes back into the intake.

One thing I DID do was modify my maxspect Gyres.

I am running them in opposite corners, as "half sticks". Basically, running just one turbine on each motor and making a toilet bowl swirl, interrupted by reversing action.
This causes four different flow configurations.

It seems to be producing really good flow in the "toilet bowl" phase, less equipment to look at, and maintenance is much easier dealing with only a single turbine on each motor. Right now, I am pretty happy.