9002 in sump - questions...

[scolley]

I've got a nano tank that I'm building a custom sump for. It's got to go into a stand where space is very, very limited - especially vertical space. So how deep I make the sump is a critical question.

I've purchased a 9002 that I'd like to put in it, and have two questions...

1) It looks like water flow into the skimmer (maybe out) through two small slits in the bottom. So how much space needs to be between that bottom of the skimmer and the bottom of that sump for adequate flow?

2) The water level mark is approximately 8" from the bottom of the skimmer. But I've read that USA models work best when the water line is 1/2" below that. So how deep does the sump need to be, including the space needed for my first question above?

I'd love to just make my sump 12-14 deep so that I had enough vertical padding that it didn't matter, but I just don't have that much room. Every inch counts.

Thanks in advance.

 

[rvitko]

I would make it 8" deep so you have enough room for some adjustment. The bottom slits need some space but there is no active flow in or out, it works on diffusion. The water inside the skimmer is depleted of dissolved organics, so more diffuse in, in much the same way as sugar dissolves in tea and the tea has the same sweetness throughout, solvents (water), distribute solutes evenly and as it is pulled from one area the molecules and ions will redistribute to be evenly dispersed.

 

[scolley]

Thanks Roger! That's EXACTLY what I needed to know.

Designing the sump to have the 9002 sitting in 8" of water means that if it were resting on the bottom (I know - don't do that), then the water level would be just about 1 cm above the top of the water mark on the unit.

So assuming I make sure there is a little (1 cm) water under the unit, then I'm cool at 8+ as long as I never need the water level higher than the water level mark on the unit.

And if I need to raise it - so be it - I've already done every thing I can to reduce the height requirement. And FWIW, I can raise the unit as much as 1.5" off the bottom (water level 1.5" below the water mark) then still remove the cup, and get it out of the sump and stand. Just barley. And "just barely" is the same thing as "it fits"!

Does it sound like I'm OK?

 

[rvitko]

Yes, and keep in mind if you have an 8" baffle, usually the water level is about 8.25, 8.5" before it falls over, I think you will be fine.

 

[scolley]

Thanks Roger. That's a really good catch! As a newbie to sumps, I wasn't sure how much height that would add. But the flow through that portion of the sump will be pretty gentle... only about 125 gph. So I'm hoping that will minimize the extra height of the water due to the baffle.

And that baffle IS set at 8", but I think I'll leave it. Based on your comments, and extra 1/4" to 1/2" won't sink me. And I suspect it will be on the low end of that anyway.

Thanks for the help! Just what I needed. Thank you sir!