Tank flow improvements

[dakar]

We just moved to spray bars on each side of the tank, one powered by a Mag7 and the other by a 9.5. (the Mag7 needs to be replaced by another 9.5 it's weak). Holes blowing both across the surface to the front of the tank and some blowing down from bottom of the bars. All I can say is, Wow what a difference! Angel keeps things very tidy in there, but when I first fired it up, you could see the crud litterally rolling up into the water to be grabbed by the overflow. I got some pics I'll try to post this evening if time permits.

No more ugly powerheads to clutter up thing walls, and fall creating massive sandstorms and general havoc on the reef. Looks like great flow everywhere in the tank with varying areas of med to high areas. Haven't found any real dead spots yet.

I changed out the weir box to a monster that's using two 1" downpipes... talk about the ability to move some water! Both return pumps running full bore and the downpipes can handle it with plenty of room to spare.

Just need to whip together a new skimmer or something to feed the downpipe directly into to manange all the microbubbles being generated by the new downpipes. Might as well use all the air for something productive like skimming. The turnover rate is so fast the bubbles don't have enough time to rise out of the sump before being sucked up into a return pump and filling the display :( But without doing any real math I'm guess turnover through the sump is now is close to 1000gph or more.

[davejnz]

Any ideal what you tunover rate is for this tank?I'm gettin about 45x in my 40 and its barely enough for the biotope i'm trying to create.Water movement is second to only lighting in a reef tank IMO and many algae/nutrient issues can be solved by increasing the flow.

[dakar]

Calculated it out and right now It's pushing near 1200 gph through the display and sump, with 500gph through the refuge (split sources between the display and sump). Though probably enough for the softies and LPS, I'll be adding back a couple more powerheads in the tank for a little while

I still need to increase the turn over a bit more. From all my research I need to get the display alone well up over 2000gph. The brainstorm idea of putting two downpipes from the weir box was not the brightest thing as there is no real way to balance out each pipe without using a valve on each one, right now it's either 95% full bore on one side or the other, going to pick up a couple ball valves tonight and see what kind of damage I can do.

Likely I'll scrap it and build two new separate boxes, sure seemed like a good idea at the time, just didn't put enough thought into the physics of two downpipes from one box :( What I need is a 24" bandsaw and solid fence to cleanly cut it in half to make it into 2.

[davejnz]

I still think 2000GPH is too low,I would try to get it to 4500GPH in the display(not through the sump),that should give you a 25x turnover rate.Check out those SEIOS pumps by RIO,they can really put out some flow and aren't too expensive.They provide a dispersed flow unlike the streams that MJ1200's put out.
25x is about what i'm getting in my LPS tank and it still could probably use a little more.

[jerryc]

I agree with Dave i have about 28 to 30 times and not to much like to have more
with the Seios you can have a lot with out pushing things around.

[dakar]

Thanks for the advice... I'll have to check into them, so long as they aren't too proud of them like some of the Tunze systems I looked at.... they were really sharp with a lot of cool features and put out great flow patterns, but the price tag made me take the checkbook and run for cover.

Suggestions for flow patterns for such a large tank?

Guess the what used to be recommended 10x turnover rate no longer applies huh? 25X or better... Wow thats a lots of water :)

You guys think 1200-1500gph through the sump is high enough then?

[davejnz]

sure,the flow in the display is where its needed.I bought my Seio 820 for $40,they now make them in a 1200 model too.1200GPH is pretty good for an in tank pump.A pair of those would serve you well.

[dakar]

oh cool... somehow I managed to overlook their products completely... the Seio M1500 -1500 gph runs about $65. A couple of those oughta really help some things out. Thanks!

Now i have to remember where I stuck this little tid-bit of info for the next time I order toys :) Time to update my pumps chart too I see, lots of new pumps out there now.

[jerryc]

Just one thing the Seio cant be run on a alternating devise or controllers. But i
like them anyway