Internal bio filter

[Dutch Dude]

Hi everyone,

I'm a enthousiastic fish keeper and decided to do some DIY projects. I'm building some stands right now and next step will be hoods for the tanks. I like to think ahead and did look for some info on filters. I would like a small internal filter with long periods between cleanings so the filter will work as a good biological filter. The filters will be running in tanks of approximately 50 gallon, 75 gallon and 90 gallon. I came on 2 possibilities and I would like you're opinions on both types. The size of both filters will be the same and approximately 6 inch x12 inch x height of tank and placed in one of the corners.

Filter A has a big filter surface and the water will have a low flow rate and for that a long period contact with the media. Because of the large filter surface I'll expect a longer time between cleanings and the dirt is spread on the whole surface.

Filter B has a smaler filter surface (half the surface of B) and a higher flow rate. The way the water has to travel is much longer than filter A. I'll expect more often cleanings becouse of the smaller filter surface.

The flow of the pumps will be abouth 160 gallon / hour (600 liter / hour).

What filter would you prefer and why?

Here the link to a oldfasion drawing

http://img467.imageshack.us/my.php?imag ... 896cb6.jpg

[Dutch Dude]

Here the pic



I look forward to the opinions and aditional info.

Ruurd

[Bas Pels]

Hi Ruurd,

I would like a small internal filter with long periods between cleanings so the filter will work as a good biological filter

I would like that too, but the very best way to expand times between cleaning is a bigger filter. As you wrote yourself, after a certain timeperiod, any filter will work biologically. This will result in much larger episodes between ceanings.

Personally, I have internal filters measuring between 5 and 10 % of the total content of their tank, and these can almost do without cleaning for a year. In fact, I have installed some 12 of these filters 2 years ago (tis week 2 tears ago) , only working with the well known blue mattrasses. I think I have not rinsed half of the mattrasses, but onty 2 out of each 5.

Besides, I hardly rinse them, because I squeese them two or tree times, than I let them oxidise in the air, and after 3 months they are almost clean. I squeese them another 2 times and they are ready for use.

Bas

[Dutch Dude]

Hi Bas,

How are you doing? After our phone call last week I did found some info on you're filters (on forums) The tanks I have planed are not that big and the tank of 75 gallon (300 liter) will be the home of some Gymnogeophagus. I have to benefit the length of the tank (to create enough hiding places and enough room for several territories). My original plans were filter B. After seeing you're filter I began and calculate it down to a smaler tank size and turned it 90 degrees and work with an overflow. The result is filter A. If I compare I with yours the average flow will be of the same order just like the way to travel through the foam (thickness of foam) and the surface. The filter volume is abouth 7 % of the tank volume. I hope I didn't make mistakes in the calculation

If you have to evaluate both filters,...what would be you're choice and why?