One SCWD or Two??

[ReefDreamin']

Hello All,

I am trying to figure out how to setup my sump...no tank yet, just in the planning stages. I would like to use the lifereef over flow to get water out of the tank and into the sump, but I have a question about the return. I have read some nice things about the SCWD wavemaker, but I was wondering if there is any benefit in using two of them and splitting the return flow? Will this even work? I have attached some (not so great, I know ) sketches that I would like some opinions on. I will be using a MagDrive 9.5 and the water will have to travel about 4 feet to get back in the tank, plus the 90 degree bends. Will the 9.5 enough? Should I go with a 12 instead?

I don't even know if the SCWDs work if you have them connected so far away from the pump....if anyone has any experience with using these in a closed loop type system please help!!

 

[Anonymous]

I think your diagram is pretty sweet. I don't know the ratings of the pump you listed, but I shoot for a minimum of 10 times the tank volume per hour in a reef tank. 20 times is even better.

I also always use 2 return pumps rather than one; if one fails, (and one eventually will) you still have one pump going. I would do 2 SCWDs and 2 pumps.

 

[ReefDreamin']

Thanks Matt

Two pumps sounds like a good idea, I didn't think of that - I'll have to figure out if I can fit another pump in the sump though. It's already pretty tight with just one pump since I want to throw an AquaC urchin in there and the heaters as well. There is always the possibliity of the HOB Remora instead of the Urchin...or maybe two external pumps instead of submersible? Uggh...I'll have to figure this out.

If anyone else has any advice/comments, please share...thanks!

 

[ReefDreamin']

Ok, so here's my new sketch with two SCWDs and two MagDrive 9.5s. Taking into consideration the 90 degree bends and the distance from the sump to the top of the tank, I should get about 20-23 times the total water volume to circulate every hour. I changed the size of the compartments in the sump to make room for the second pump. This still leaves room for the heaters and skimmer.

My one problem now is this....will two MagDrive 9.5s have too powerful an intake for a 10g sump? Each pump has a flow rate of 950 gph at 0 head pressure. Am I asking for trouble here? I'll post this in another thread if anyone is interested in responding. If you have any thoughts about my SCWD plans, please post them here.

Thank you!

 

[tangir1]

The issue here is the overflow in the main tank. If it can handle the flow, you should be fine with the two pumps in the little sump. May need to lower the overflow a bit so that it can dump water down to the sump fast enough without overflow it when power is out.

I used to run two magdrive pumps as return without making a mess. I mounted them on a piece of plywood externally, and use a tee fitting to combine the inputs into one large diameter PVC U-tube. Just make sure the pump is below the waterline in the sump, and you won't need to prime it more than once.

BTW, my sump is 60 gal, so space is not the reason I did that. But I feel it is something that you maybe able to gain something from my setup, FWIW

 

[Anonymous]

You may need to buy a second overflow, or add a second U tube to the existing one. Only way to know for sure is to fire it all up and see what happens.

 

[Baianotang]

Go with the two mags and skwd soo cool.

 

[tangir1]

>.... Only way to know for sure is to fire it all up....

I have a feeling that most overflows used in a tank of that size won't be able to handle two magdrives...

 

[vair]

Can't help you on the to much flow issue. I have two pumps and two SQWD's and it works great go for it, just add some valves so you can regulate the flow. I actually have three SQWD's the other is on my return from the chiller not in the sump.

Dave

 

[ReefDreamin']

Dave, what size tank/sump do you have? My concern is that two pumps will be too much for the size of my sump. I had another thread going about the size of my sump and tank vs. two MD 9.5s and a lot of good points were made by other posters, especially about the amount of heat given off by the pumps, which is substantial. Because of this it would probably be better for me to go with an external pump.

Tangir1, I attached another sketch with a MagDrive 12 or 18 used externally in the other thread - I don't know if it is similar to your dual pump set-up, but perhaps you can take a look and give me some pointers...I'll attach it here as well. The overflow issue needed to be addressed too, so I figured I'd go for a dual overflow to keep things balanced.

 

[tangir1]

In addition to the U-tube mentioned above in my post, and illustrated nicely (great illustrations, BTW!) in your picture, you may be able to drill the sump (good call on the 10->25 gal, you need the bigger one if you can fit it inside the stand) and use a bulkhead so that you never have to worry about the U-tube loosing siphon. In fact, that's the prefered method cf. to an U pump intake.

One other thing is that you may want to have the overflow in the middle of the tank, and have the returns on both sides of the tank.(2-o-o-2), or a 3-o-o-1 setup... whatever fits your fancy.

 

[vair]

I do have a bigger set up so you might be right: 110g. tank and about 70g. sump, my pumps are 2 X Aqua Medic OR 3500's I don't have a heat problem due to my chiller and yes that could be a issue but a had no problem with heat from the pumps before the chiller. I've always had submerged pumps they are real simple, take up less room. When I upgrade to a much larger system I'll for sure go with external pumps. As posted before it is nice having two pumps, two external pumps IMO would be overkill but I really don't know. If you went external pump I would have the sump drilled for the pump return instead of the U tube.

Dave