700 gal system in the works. Need Help

[noledoc]

Howdy Folks,
I've got a 12 ft x 36" x 25" tank being built that will sit perpendicular to a 7 ft x 36" x 25" tank. The seven foot tank will serve as a refugium for the larger tank. The smaller tank will be divided down the middle with the front half a heavily planted area designed to reduce nitrates. It will also house shrimp and Nano type fish such as Celestial Pearl Danios. I'll also light it up at night so as to reduce the nightly drop off in O2 etc.
The back half of the tank will house the filtering, UV, etc.
I've got several questions:
Since I will have a vast area in which to filter my tank water, and I do intend to have mucho filtration medium in it (such as 480 nylon pot scrubbies), etc, do I have to circulate the system's water 4X an hour? My reason for doubting the conventional wisdom about tank volume 4X/hr is the SIZE of the filter. If I send 1400 gals thru there an hour, shouldn't that take care of my biological filtration needs?
Another concern is the flow of water. If I go with 4x tank volume (700 total gals including the sump) I would be pushing .77 gal / second. That's almost white water. Most of the flow would be directed thru the back half of the seven ft tank where the front tank that's heavily planted would only get about 1/4 of the flow.
Anyway, thanks a heap for the help.
Paul

 

[kendragon]

I don't consider pot scrubbies as macho filtration medium. There are a lot of other mediums like ceramic, K1, Matala,...
What do you plan to stock? I flow 3500gph through my 225g tank which is over 10X for pbass. No white water rapids even can be noticed. I'm no expert in plants but I think too much oxygen is not good for them. So maybe high turn over rate is not for your tank.

 

[haywood]

I would go really heavy on the plants on the 7' tank and add most of the heaters and filtration on that side. On the 10' tank I would add a couple of canisters and a couple of powerheads. You gotta post pics of whatever you do. What will the stock be?

 

[noledoc]

I don't consider pot scrubbies as macho filtration medium. There are a lot of other mediums like ceramic, K1, Matala,...
What do you plan to stock? I flow 3500gph through my 225g tank which is over 10X for pbass. No white water rapids even can be noticed. I'm no expert in plants but I think too much oxygen is not good for them. So maybe high turn over rate is not for your tank.

Hey, thanks for your input. I had ordered scrubbies from a place I found a set of 24 for under $4. I got 480. I will have plenty of room in the 1/2 of the seven foot tank. I plan to pack that 140 ish gal with bio medium. I've already ordered two, ten foot mats 24" wide of 1 inch filter foam. I'll use some of that for a mech filter and the rest as bio medium. I might put in a section for an UG filter as well.

 

[noledoc]

I would go really heavy on the plants on the 7' tank and add most of the heaters and filtration on that side. On the 10' tank I would add a couple of canisters and a couple of powerheads. You gotta post pics of whatever you do. What will the stock be?

My big question is do I need a 4x/hr flow rate if I have such a massive biological filter?
I think a few power heads in the big tank would be helpful. To make sure the plants have a constant source of nurtrients. Thanks for your feedback. Once I get started I'll keep pics.