Question 2, water flow and designs for reef tanks

[hawk]

Originally Posted by Jason McK

I believe that volume of water can be improved if power heads are not fighting each other. Try and promote flow that is not impeded by another flow pattern. This allows you to use less gph and essentially get the same results.

J

This is a good point. All too often it seems we are overly concerned about gph , adding ph after ph trying to get rid of dead spots. If the ph's are pointed towards each other you'll end up with a swirling type flow, although somewhat random it dies out quickly, The flow from the ph's essentially cancelling each other out. The newer ph's on controllers avoid this if set up to do so. After talking with Paul at Oceansmotions about my closed loop I decided to have my sump return(Dart) over the top split into 4-3/4" returns aimed down the back towards the bottom. Then 4 cl openings on the back wall near the bottom shooting water towards the front. 3 cl openings on the bottom about a third from the front shooting water towards the top front glass. This water bounces off the top eurobrace, back toward the rear of the tank and into the overflows. One more cl opening on one end. This one I'm still experimenting whether to have it aimed directly towards the opposite end or towards the top front rebounding toward the back. Almost all the rock is on pvc racks enabling the flow from the closed loop on the back to shoot under the rocks towards the front. The cl is on a Oceansmotions 4-way and Barracuda. So far I like this set-up. There are no areas that are blasting 24/7 but rather large amounts of water moving in concert with each other in alternating patterns. It takes about a week before there is any noticeable collection of detritus on the BB and then only in a few spots, which is easily vacummed out. The tank is 375g 8'x30"x30"

[vanreefer]

I have read multiple times from respected marine biologist types (Calfo et al.)that flow is second only to water quality in importance in a closed system. It makes sense really that in order to deliver nutrients etc that are in the water collumn you have to have good flow... I currently run a Dart on a CL with 4 outs 2 on the bottom pane of glass directed at the front of the rockwork and 2 on the back pane blowing behind the rockwork (soon to install the PVC rock rack)... return from the sump at about 900 Gph after head blowing at the surface for aggitation and finally a Tunze 6100 on a single controller... I notice way better polyp extention than I had ever seen when these corals were in my old 75 with way less flow (2 months ago)... furthermore I have the Tunze pointing toward one end of the tank and the polyp extention is greater on that side of the tank, which makes me believe that the corals are happier over there... time to ask the wife if I'm allowed to buy another 6100... oh and then a multicontroller... oh and then...and then... I wonder why i'm always in trouble??