What should I put in my bio filter?

[mgmine]

There is so much information on building a bio filter that I am overwhelmed and would like a few suggestions to get me started. My pond will be 12x17 with a free form shape, It will have some fish and some plants I am not sure how many. I acquired a 200 gallon tank that is 38" in diameter and 30 inches long. The water will go in from the bottom and come out the top although it could go the other way. The question is what should I put in it? I have seen packing strap and snow fence and just about everything else talked about. I am assuming that I need layers so what should they be and how thick should they be and at which layer should specific material be placed? I am looking to do this the cheapest way since there is so much of an area to fill.

 

[dieselplower]

If that were mine I would get a bulk load of gravel.

 

[Mucky_Waters]

Nice tank.
What sort of mechanical filtration are you planning?

 

[HTH]

Obviously everyone has their favorite. Are you shooting for max bio filtration or cheap/free ?
Is there a budget?

 

[sissy]

gosh if you paint it you have the makings of a cow .Wish I could find a tank like that

 

[Sunshine]

My bio filter is an upflow also. I have a bag of bio balls and 3 blue matala mats.

 

[JohnHuff]

Wow, that thing is huge! It could be it's own fish tank!
If you are looking for something cheap, it will have to be something you buy in bulk. Snowfence would be cheapest I would think, that you can buy as a consumer.
Anything plastic and doesn't deteriorate would do. I would also suggest polyethylene beads that manufacturers use. That would be cheap if you can get a source for them and perfect for something like this. Most importantly, they would be easy to flush clean. But you'd have to buy that from a plastics manufacturer.

 

[dieselplower]

Nice tank.
What sort of mechanical filtration are you planning?

This is a great question. Depending on the answer my answer might change.

 

[mgmine]

I picked the tank up for $75 dollars plus $25 for delivery, they sell similar ones at Tractor Supply for $500. I hadn't thought about mechanical filtration I thought that something like scrub pads would work but then again I'm not sure what mechanical filtration does or where in the line it would be installed. I'm shooting for the cheapest way I can filter things. I went to a pond store and they had 12" square X 2 " thick scrubbing looking pads 10 for 12 dollars. If I only needed one thickness it wouldn't be a lot but if I need it say 24" or 36" deep then it would quickly add up. I thought about gravel but it would be a pain to clean.

 

[JohnHuff]

If you use scrubby pads, they would be your mechanical and bio filtration.

 

[mgmine]

How thick of a layer would I need? Would they sit on top with something else made of plastic like snow fence below the pads?

 

[HTH]

Mechanical filtration catches solids. The more solids you have the faster they plug up. There are quite a few variables here the main one is where you put the pump. If you use a submerged pump you will have a input screen or sponge which will stop some of the solids.

I like something along the line of a settling changer. That way you can just drain the stuff off the bottom.

 

[mgmine]

I have a submersible pump does that mean I can get by with just a bio filter? I plan on building the skippy style with the settlement chamber on the bottom along with a 2" drain or possible the Doc filter that I read about in the sticky section.

 

[HTH]

Yes but it will collect what solids the pump passes.

The distinction between mechanical and biological are rather artificial. Generally both types do both types of filtering.

Let me use an analogy as to why we make the distinction. In wood working we always do the bulk of the cutting with the tool that is easiest to sharpen to minimize the amount of time we spend sharpening tools.

If filtering we want to catch the bulk of the solids with the easiest to clean filter to minimize the time we spend cleaning filters. It is a lot easier to open a valve and drain a settling tank then to remove and rinse scrubbie or buffer pads.

There are methods to make cleaning easier like back flushing which is great when it works.

 

[JohnHuff]

Well, that's like saying you can use your mountain bike to road race and your road bike to go on mountain trails. Both bikes(filters) can do the other's job but it's not recommended.

The mechanical filter is used to filter out solids. You can use it also as a bio filter but it won't have as much surface area as a dedicated biofilter.
The biofilter has a large surface area for bacteria to grow on, but you don't want it clogged up and it is not set up to be easy to clean.

If you have a submersible pump such as I do, you should have a mechanical pre-filter in front of it so the solids don't clog up your pump.

The distinction between mechanical and biological are rather artificial. Generally both types do both types of filtering.