DIY Filter layout : for very large tanks

[medicineman]

I'm building XXL aquascape that filter must be custom made to meet up the capacity of mechanical and (most importantly) bio filtration. The filter I'm planning holds about 400-500 L or roughly around 20% of the main tank's net volume (expected to be 2700-3000L). The filter itself will look like a huge tank which is separated from the main tank.

Issues to discuss:
A. Pump L/hour rating to use to get optimal flow/filter turnover rate
B. Layout

1. Water inlet from overflow
2. Filter chambers
3. Backwash drains with individual pipes and valves
4. Overflow to drain (water auto level control)
5. Outlet back to main tank
I need your comment and advice on the layout. Each chamber will be filled accordingly with filter media. From up to bottom, first chamber with coarse material such as filter brush or mat and lots of ceramic bio ring/bio balls or coarse pumice. Second chamber with coarse sponge and porous pumice. Third chamber with fine filter floss and coarse sponge filter. Last chamber will be left with no material (only a single pump).
The backwash drains are there to ease up maintenance, usually the most clogged part will be at the bottom (due to the design) and opening the valves (and sometimes with some gentle stirring with a stick) will restore flow significantly. Each backwash hole will be topped with coarse net-like material to avoid filter material from getting stuck or sucked out to the drain.

So what do you think?

[bossteck]

Hi,

You have a well though out design.
Just a suggestion, you might want to include a t-joint in your outlet (section 5) with a ball valve. That way, even if the pump you get end up to be too powerful, you can divert some of the water from the outlet back to the first chamber or to last chamber (depending on how far you want to extend a pipe
from the t-joint). By doing this, you will not compromise the pump.

Cheers!

[BFG]

Medicineman, point number 4 might/might not be applicable for a sump setup. Usually, when evaporation occur, the water in the sump will fluctuate while the water level in the main tank will stay the same.

Can I have more information about the tank setup, equipment to be used, where the tank would be located etc,etc?

[medicineman]

@BFG
The filter is going to be used in pair with a pond garden, which is built integrated with our house. It seems you know well that this leads to something interesting and out of ordinary

Point #4 will certainly work very well because I plan to do a slow rate bleed and drain method, which is simply adding small amount of fresh water to the tank and let the excess drain away from the overflow. This, I hope will reduce the dependency of doing massive weekly WC (which is a major problem when your tank is very big). The only time I need to do manual WC is during vaccuming, which is several months apart.

You can see the whole project at neighbour's forum

http://www.plantedtank.net/forums/ph...n-project.html

Perhaps I will also post it here for comments if I have the time.

@bossteck,
thoughtful. But still choosing the right pump will be crucial, better pick it right than to waste electricity. I will still install a T connection and a valve to fine tune when neccesary.


OK... now does anyone know how much turnover rate per hour (in %) is optimal? (as in average tanks)

[BFG]

Medicineman, have you thought how the water running down from the cascade would affect the splash area? To prevent from excessive co2 loss, I would think the use of 2 separate pump, 1 for the waterfall and another for the display area.

A pressurized pump like the Iwaki brand might be used for the water cascade feature. It may have the strength to push water up that high but I do not have the spec for the model. This is what I know off hand. This pumps should be use out of the water so you'll need it to be plumbed to your sump/filtration unit.

The return pump into the display area however is another issue. I do not know if a co2 reactor would be plumbed in line or are you going to use a co2 diffuser into the display area. The single pump might/might not circulate the water in the display area that's why I would recommend to get a circulating pump. Tunze has some circulation pump that can push volume of water around and in some model, it can be controllable. It was primary designed as a wavemaker for a marine setup but seeing your display tank, it is still adequate.

[medicineman]

A dedicated smaller pump to handle DIY inline reactor (3-4" pipe) will ease the filter pump's work. Diffuser would be strange enough for this scale. I will need up to 8 to even out... and that would add too much sparkle