Probably a question for Otter, but if anybody else has any experience please chip in.

I am introducing additional planting basckets into my 'newish' pond and am going to make them up as biocenosis-pots as per the Anoxic filtration principle. These filter pots are to be in addition to my standard external particle and biological filters.

From the information that I have read on this system I had anticipated that the cat litter used in the planting/filter pots would remain in it's original granular form thus allowing a throughput of water. I have bought some cat litter (which I believe met the required criteria)and tested it in Water, within half an hour the granules of clay had brocken down into a vey small particle size.

My question is should the cat litter break down in this way or have I bought the wrong product?

Regards

Iain

Cat Litter!!!!!!!!! Please explain how this works please.

I haven't tried this myself, Iain, hence I can't answer your question from experience. As I understand it, the important thing about cat litter is that it retains its crystalline structure. If the material you have turns mushy, it's not going to work. But if the smaller bits are still hard, maybe you've got the right stuff after all. I took the liberty of reposting your question to another forum where the inventor of the system and several who have tried it are participating.
http://www.koiphen.com/forums/showthr ... 2640&posted=1#post1632640

Quote:
As I said, I'm just learning about this myself. But I'll give you a brief (oversimplified) description.

Though the first thing you'll notice about this filter is the plants, it's primarily a bacterial filter. Ponders short on land have put the pots indoors in a tank without plants or sunlight, and it still works. Nitrifying bacteria live in the outer layers of cat litter and convert ammonia to nitrate to nitrite, just like in the more familiar aerobic filters. But in the center of the pot, where there is only a little oxygen, denitrifying bacteria convert nitrate to nitrogen gas. Bacteria in this anoxic zone will also metabolize phosphate which will help control algae. Transport into the pots is accomplished by molecular diffusion and the attraction of ions to opposite electrical charges rather than by water being forced though the substrate. Hence it won't clog (and perhaps the fine clay granules are acceptable).

For a more complete explanation, read this:
http://www.mankysanke.co.uk/html/anoxic_filtration_system.html

Jason,
I'm glad that Otter responded to your post, that is a far better explanation than I could have penned.

If you read through the links that Otter has attached you will get a better understanding of the system (you will probably need to read it a few times, it's very technical in places). If you then read a bit wider on some of the other Koi forums (just Google 'Anoxic filter') you will find that it is a very controversial solution, many people have very strong opposing views.

I'm looking at this from a rather more simplistic view. The filtration on my pond is a 'traditional' external particle filter and biological filter. In my opinion it is impossible to have too much filtration (i.e. the more the better). If I can add to the total filtration in my pond simply by selecting the correct type of 'soil' in my planting baskets then why not do it?

If the theory works then I have improved my total filtration.

If the theory doesn't work then I have lost nothing. Cat litter is 100% pure clay (don't buy anything with other additives). It is quite normal practice to plant Lilies in clay, indeed some bare rooted plants that you can purchase come complete with a bag full of pelleted clay in which to plant the lily. The only other ingredient used in the Anoxic filtration system is Laterite, which is a natural product used as a growing medium in fish tanks. Both products are (in my opinion) 100% safe and don't cost significantly more than purchasing bags of aquatic compost.

I don't have the technical background to determine for myself if this system works or not. The scientific explanations in support of the system are very detailed and quite compelling, yet there are many very strong oposing views. From my simplistic viewpoint however I have nothing to loose by using this medium in my planting baskets.

Regards

Iain

So far, it's not looking good for your crumbling cat litter, Ian.

Quote:

After wading through a great deal of heated and not very cogent discussion, I decided that the system probably works as advertised. Were it not for the few who tried it on their own ponds and posted their results, I might have given up trying to sort fact from hyperbole from wild misunderstanding. But everyone who actually tried the anoxic filter and posted about their experience reported extremely good results. Now, I didn't find very many of these people, but there were no experience-based posts at all to suport the aneaerobic-bacteria-will-kill-your-fish crowd. Also, after reading the CD book, I realized that none of the people objecting to the anoxic system actually understood it. Nearly all of the objections are based on incorrect assumptions, for example, that there is stagnant water in the filter, or that the plants do the bulk of the filtration. In the absence of a convincing theoretical problem, and with reports from actual ponds being 100% positive, I'm willing to take a chance. And as you say, we have nothing to loose by trying a new planting medium in our existing ponds . . . unless you believe that evil bacteria live in the hearts of pots of cat litter and that these foul hordes will suddenly charge out to attack any fish unfortunate enough to share the same water.

There are so many different kinds of cat litter on the market here it can't be easy to determine which one is meant even if you stick to ones described as 'natural clay' which is presumably what you have bought and has crumbled ... a UK brand name would help you! Should it be orange/brown or grey in colour - knowing that would help?

Otter,
Thanks for copying my post to the Koiphen site, I'm waiting for my registration to be authorised so can't post direct on there (I've re-applied today).

I think that the response to the post that you placed on there has answered my question, without having any real info to go on one of the posters suggested that I had bought 'clumping' litter. This assumption is correct, I guess that there must be a reference somewhere to using the non-clumping variety which I had obviously missed!

Anybody want three bags of Cat Litter??

Iain

Danzcool, from California shows good photos of PVC uplift tubes for the baskets and Kitty Litter from Wal-Mart. Gust log onto Koiphen/Anoxic Filtration this may help those that are having problems with supplies.

DrFish,
I sourced a suitable material that is widely available in the UK, it is 'Tesco premium cat litter lightweight'. It comes in a white bag with a picture of a cat on the front. There is no information whatsoever on the bag of litter as to what it contains, but I am fairly sure that it is the correct material and I have now installed my first couple of basckets.

Regards

Iain