6100s or 6200s?

[luminary]

Roger,

I'm in the process of setting up 72"L x 36"W x 20"H tank. It's going to be a barebottom mixed reef. Other than the pump return (approx 2000 gph split in two), the only water movement I'm planning on is two streams.

The tank is a peninsula tank with the overflow in a wall on one of the 36" sides. The streams will be situated on the overflow side pointing down the long length of the tank. They will be controlled to oscillate. My first thought was to go with two 6200s, but my LFS (whose opinion I highly respect) feels it's overkill and I'm better off with 6100s.

What would you recommend?

Thanx...

 

[rvitko]

The 6200 is just a wider flow pattern than the 6100 but no more forceful. I would use the 6200 if the tank will have mainly SPS, otherwise the 6100 so you will have weak flow areas.

 

[luminary]

Is it documented anywhere what the flow pattern looks like for each of them? Something that shows what the "cone" looks like for each? Given that it's a three foot wide tank, I want to make sure that it's adequately covered.

 

[rvitko]

It flares out pretty quickly to give a cylinder of flow that is 7 by 2 ft for the 6100 and 7 by 2.5 ft for the 6200.

 

[luminary]

Thanks Roger...looks like the 6100s will be perfectly fine for me.

Just out of curiousity, that extra .5 ft spread accounts for the 2,000 gph difference? Seems like with such a significant rating difference (and power consumption difference), the flow would be stronger as well...

 

[rvitko]

I try to explain it to people like this, if you have a 1/2" garden hose you get a fairly forceful stream of water, now if you put a firehose on your faucet it would just bubble out. The surface area increase from that extra .5" in diamtere is appreiciable, so the flow is much more diffuse than from the 2" outlet. Unfortunattely the bigger the pumps get the more losses their are in efficiency, the mootor coil is bigger, the transformer is bigger, all these coils of wire being larger increase resistance so more power is needed.