please help ...is this enough or to much flow

[INTEGRAKID]

planning a 29 aga with a 20 high sump. going to have a internal overflow to a 1" drain w/stockman pipe. the return pump is going to be a magdrive 7 going to two

1/2 inch returns at opposite ends of back of tank. possible scwd not sure need advice on that also. do i need additional flow from ph's ? 2 mj 400's at each end w/hydors on them ? tank is going to house zoos, shrooms, lps only. als ohow large of an area should i make overflow ? any advice appreciated. should i have ball valves somewhere in plumbing ? check valves anywhere ? bought tank today having it drilled next week. making overflow this weekend out of black acrylic . 1/4 acrylic ok ?

[pheallox]

I have a mag 9.5 with a scwd as a return on my 29 hex it is nice all you should realy need. as for every thing else look at www.wetwebmedia.com and www.malevsreef.com they hav nice info and mark has a vidio on malevsreef.com of his 50 with a scwd with a 7 so you could see it in action.

[INTEGRAKID]

Bump....

no other opinions ?

[wwildcats04]

qtr inch acrylic is pretty thick used 1/8" on mine you can see it from the link in my sig. I like the scwd but have heard bad things about it crapping out on people I think the 1" drain will work well with the 7...

[Gill Snork]

I just set up a 20 high with a Mag 7 and a SCWD- flow is perfect with 2 3/4" outlets with a top and bottom outlet on each side inside the tank. Your tank is a bit bigger, but not by much. 1" piping may be a bit big since the outlet of the MAG's is less than 1/2 "ID- you'll never get more out of the pump than through that outlet, bigger is not always better. A couple suggestions:

 

1. you should include ball valves before and after your SCWD so you can remove it for cleaning and one before your pump (and a drain tee at the lowpoint between the valves and the pump if you are smart) for removing and cleaning. I like having full functional control of the flow from the pump and each branch.

 

2. When starting up your system, close the inlet ball valve to the SCWD before you turn the pump on- the SCWD can't handle the shock of the pump. After its running, slowly open the valve.

 

 

3. Also, you can port the inlets and outlets of the SCWD to flow a bit more. And if it breaks and you are handy, do a search for SCWD mods on this site- there is a listing of people who modded them to work better after failing.

 

Gill

[INTEGRAKID]

What about check valves on returns to prevent a siphon back into sump ? also is there a possible problem with the 1" drain ?

how high up should the overflow box be ? sorry i'm kind of dense on this subject. i'm more of a laborer than an engineer..lol . I'm more than capable of building stuff off of someone elses plans. On occasion i can even come up with my own design.

[Gill Snork]

Check valves are a precautionary measure and may help, but in my experience (I do design work for Dupont), we do not trust check valves to be leak proof and they often fail- especially when you can get algae growth to inhibit their function. But if it offers a peice of mind, go for it. I think if you make your design your overflow to not function (loose siphon) below a certain water level, you won't have to worry about overfilling your sump and a check valve on your returns wouldn't hurt, although they are not foolproof.

 

As for the 1" drain, that is a good size for the system you describe. You want to "flood" the suction of your pump as much as possible so it can supply the maximum head and flow and not have to "pull" the water into the pump. Oversizing there WILL help, but not so much on the outlet. Seems a bit backwards, but its a fact that I deal with and design around on a daily basis. Think of it this way, if have a 1" pipe with a valve at the end that is half closed (or half open) will it matter if the pipe after the valve is 2" or 5" ? You will only get the flow from the limiting agent- aka the valve. In this case, its the pump outlet size.

 

Gill