Calculating how much K1 needed for a fluidized bed filter

[madmark285]

From  AQUAHOLICS AQUARIUM

Quote

The amount of K1 required for your aquarium depends on the size of your aquarium and the number of fish you have. A general rule of thumb is to use one litre of K1 media for every 100 litres of water. For example, if you have a 300-litre aquarium, you would need 3 litres of K1 media.

And from Aquarium Science

Quote

The K1 media is loaded into the sump at about 60% of the available volume.

So doing the math:

You need 1 gallon of K1 media for a 100 gallon tank and the size of your fluidized bed filter should be .221 cubic feet.

So to be safe, lets just add a factor of 2 ie: 1 gallon of K1 media for a 50 gallon tank.

So using a 20/29 gallon tank for a sump, water level ~1 foot high, your fluidized bed compartment should be 12" x 12" x 2.6". That seem very small  compared to the systems you see on youtube.

Any comments, I hope I got my math correct.

 

 

[Guppysnail]

Sounds interesting.  I hope you journal your build. 

[madmark285]

On 12/10/2023 at 6:00 AM, Guppysnail said:

 I hope you journal your build. 

Yes I will.I was going to write a journal for my T-34 Sump but after I built it, I came up with a better way to make it. I am trying to design my sump filter which does not require a fully equipt shop ie compound miter and table saws, routers, etc....

 

[gardenman]

There is no magic number. Bio load matters more than tank size. A one-hundred-gallon tank with a single neon tetra in it that only gets fed the bare minimum every other day and has a single floating plant probably doesn't need any extra biofiltration. A one-hundred-gallon tank overstocked with ten full-grown Oscars that get fed multiple times a day might need a hundred-gallon sump filled with K1 and barely be able to keep up. An old, established K1 filter will handle a larger bio load than a newly set up K1 filter. A heavily planted tank that's been established for years can use a much smaller K1 bio-filter as there are massive bacteria colonies all through the tank.

And K1 filters are moving bed filters. In order to move, the K1 media need space. If you cram a gallon of K1 media into a space just large enough to hold it, but with no room for it to move, it won't be as effective as it would in a larger space. Too large a space and the K1 may not move as energetically and clean itself.

When in doubt about how much bio-filtration to use, I always err on the side of more. I've got three small sponge filters running on my heavily planted ten-gallon tank that has seven CPDs in it. It's ridiculously overkill, but more bio-filtration is better than not enough. And when I set up a new tank, I can just move an established filter to that new tank to help seed it.

A lot of people want to make fishkeeping into a science with an exact formula to follow. There are just way too many variables for that to ever be possible. Everyone's water is different. Every tank's bio load is different. Every tank's colony of bacteria is different. Every tank is unique. You need more focus on general guidelines than precision when it comes to fishkeeping. Build as big a K1 partition as you can and hope for the best. It's hard to have too much biofiltration, so err on the side of more is better. If you only have a little space, try it and see what happens. Maybe you'll get lucky, and it'll be enough space. What works for you though may fail miserably for someone else doing exactly the same thing due to differences in their water, bio load, and bacterial colonies. Fishkeeping is a hobby where there are very few exact answers to any question. What works for one person may fail miserably for someone else. 

 

 

[Biotope Biologist]

There is a guy on ebay that sells acrylic prefab sump stuff that I bought mine from for a 20H. Great stuff! Very responsive too

 

Anyway for a fluidized bed my understanding is it can be any size as long as it’s properly moving. Preferably water flow would be circular. They design fluidized media in a way too that you can have it as dense or as loose as you desire without it losing rotation. Most fluidized beds I have seen are cylindrical to allow for curved edges for the water and media to have the most efficient rotation. 
 

I think too you want a very good polishing screen prior to the bed, and debris can really gunk up and reduce efficiency of the media. Thats all I got, never built one only worked with them professionally. Good luck!

[madmark285]

On 12/10/2023 at 8:53 AM, gardenman said:

There is no magic number. Bio load matters more than tank size

Understood. Another factor, you buy the K1 media by the gallon. So it comes down to, do I need 2 or 3 gallons of the stuff. So if I use 3 gallons of K1 media in a 29 gallon sump, my fluidized bed chamber would be 12"x12"x8". That seems small compared to the sumps on youtube. But on the other hand, many of the youtube sumps seem to be an overkill. For example, we have this:

So does any ammonia reach the fluidized bed? That's alot of ceramic rings.

So for my planned 75 gallon tank with ~20-24 Mbunas, I plan on using 3 gallons of K1 media and a secondary bio filter using plastic scrub pads. I think that should be enough. For mechanical filtration, I will use 4 14" filter socks. 

On 12/10/2023 at 8:53 AM, gardenman said:

And K1 filters are moving bed filters. In order to move, the K1 media need space.

I read that the chamber should be 67% K1 media, I will go with 60% fill.