[ProjectPlywood]

Hello everyone,

My dilemma is this:

I plan on building an ~270 gal plywood tank in the near future. I have researched it a lot and feel comfortable with the build and design of the tank itself. Its the filtration system I am having issues with.

Here are the facts:
Tank will be custom built so design is flexible.
Will be injecting CO2.
Don't have funds to purchase canister filters large enough to handle the GPH needed. ( 3 x 270 = 810 GPH)

I really really like the idea of using a sump/overflow design as I could then add another 70gal or so to the tank size. I have heard however that sumps/overflows are bad for planted tanks because of all the oxygenation caused by the sump system.

So I was wondering if anyone had some ideas about a good filter system for a large planted tank. Would a 'closed' sump system alleviate some of the CO2 loss, or is it negligible in the first place?

I have also seen a design somewhere that had the overflow built right into the side of the tank (like an extra 3-4 inches off the sides of the tank that aren't part of the view screen) and I would like to implement that if possible.

Thanks for any advice, and I can certainly give more specs. about the design so far. Been trying to create a nice MSPaint image but apparently my paint skills are... well, lacking :hihi:

 

[jcgd]

http://www.plantedtank.net/forums/equipment/151121-wet-dry-filter.html

Overflow with sump is your best bet. It'll be the easiest to maintain and will do a great job. There are three setups I like personally:

Tom Barr's type, with a sealed wet/dry tower. Easy but you need a wet dry.

Wkndracer has the other two I like. A full lid on a typical sump with baffles or whatever you like OR my favorite design. Stick matten filters in a bare tank, drop some bio media in there and keep the drain submersed to minimize turbulence. Simple and easy.

 

[willknowitall]

this is what im getting, two of these stacked and a 800gph pump

 

[jcgd]

this is what im getting, two of these stacked and a 800gph pump

They are nice filters, but maintenance is a pain with them.

 

[DogFish]

If you have the skill-set to build tank, really a sump filter is no big deal. Bulkhead fittings, a used aquarium, a pond pump and some 10PPI foam. You can put your heater in the sump too.

Filtration doesn't have to be NASA rocket science to work.

 

[willknowitall]

They are nice filters, but maintenance is a pain with them.

i have one already and its no pain at all. in fact is a better design then any canister filter ive had
the fact that its top filled with air release and drain is great
no need to drag the canister to the sink and take out bio media to change mechanical media
these things are heavy duty with up to 1 inch ins and outs
hold under 15psi as well
i can shut of the intake and drain the filter on the spot ,ether though drain or existing pump

 

[ProjectPlywood]

Thanks everyone for the ideas. Definitely going to go with the sump/overflow but just try to keep the agitation to a minimum. Will put up some designs this weekend.