SPS and flow

trilinearmipmap · #1 01-08-2015, 02:53 AM

I've not decided between 2 options:

(1) The maximum possible flow tolerated by the corals, to basically eliminate the static barrier layer (analagous to insulation) of water around the surface of each coral, to maximize diffusion from the coral to the tank water and vice versa.

(2) Enough flow so that every SPS coral everywhere in the tank gets some flow. Ie. there may be excessive flow in some areas of the tank, to ensure that there are no "dead" areas or areas of low flow.

I am doing option (1) but have had edges of some corals killed when too near a powerhead. I have a feeling option (2) is correct, which is why the Maxspect gyre seems interesting - it would ensure flow everywhere in the tank without excessive flow in any one area.

The other option I thought about was just brief periods of very high flow, such as a minute of high flow every 15 minutes, might experiment with that.

Aquattro · #2 01-08-2015, 03:07 AM

I guess I'm currently sitting at option 2. I just sat in front of the tank and looked at all areas, and all get "sufficient" flow, with some maybe getting too much. It appears that all, even with option 2, have enough flow to break that barrier, if there is a barrier, and it can be broken

But all polyps out, all moving well, and sand (mostly) staying on the bottom. I think I can move pumps around a bit, and maybe even lower a bit further. I don't think the cardinals will like it now

westreefmang · #3 01-08-2015, 02:52 PM

The gyre in my mixed tank is about 50 percent with a tunez opposite and my sps polps are always extended the gyre gave lots of flow threwout even in corners there was couple lps i had to let go of as they where not fans of the high flow ive just started with sps corals so ill be keeping a eye on thread be interesting

chef · #4 01-09-2015, 04:45 AM

When I was diving in Bali and gili, I couldn't believe how strong the current was. In shallow water (with beautiful colorful sps) I was getting tossed around and thinking I could never duplicate this in an indoor reef. The water however was moving in many different directions as opposed to being "blown" by a powehead.

Myka · #5 01-08-2015, 03:10 AM

In my experience, you can have lower flow with frags (like 30-50x turnover), but if there is a point where the corals are impeding the flow then you need big flow just to keep the water column moving. It depends a lot more on aquascaping and coral growth than anything. If there are tons of corals and little swimming space it makes sense you need bigger pumps to make it across the tank, right? Some tanks are aquascaped with a ton of water space even with big coral growth, and these tanks require less flow. My old 90 had around 50-60x turnover when the corals were smaller, I bumped it up around 100x turnover when the corals were in the 10"+ range and the difference was like night and day in color and polyp extension. I am a believer that flow is at least as important as light to SPS corals. If you have good flow you can slack in the lighting department.

Aquattro · #6 01-08-2015, 03:20 AM

I agree that as things grow, flow may need to be increased, depending on the variables you mention. I can't offer an opinion on importance in relation to lighting, as I've always had tons of both in any of my tanks.
This is new territory, and I'll adjust as needed, but starting slower just to appease the fish