I am planning to build a pond in my yard in the near future and I stumbled upon your anoxic filtration system.

My name is Alex Chai and I'm from Hong Kong. I am planning to build a pond in my yard in the near future and I stumbled upon your anoxic filtration system. Let me first tell you that I pretty much failed all my chemistry and biology classes in high school, so although it took me a few times to go through your explanation on the concept of the system, I truly believed that it is the best system I've seen.  

 Anyway, there are a few questions I'd like to ask before I actually build the pond and the system. Thanks in advance for your time and any help that you can give. 

 1) I don't keep Koi although my dad does. The pond I'm building is for my turtles and since they are south American turtles which originated from acidic water (pH around 5.0-5.8), knowing that your system works on ion exchange and with my limited knowledge on chemistry, I'd like to know if the system would work the same in acidic environment? Or is it relevant at all? 

 A: I’ve tested with pH down to 5.3-5.8 and found no hindrance of biological activity whatsoever even though this is very acidic. I don’t think it will make a difference in the long run. 

 2) Space is very limited here in Hong Kong overall. I understand you gave specific dimension on the baskets and the number of baskets to be used. And since I'd only be housing 3 turtles initially (they currently live in my indoor 5.5' tank) along with some feeder fish and shrimps, is it possible to use less baskets? Or use a lot of small baskets? Or instead, use fewer baskets but make each one bigger? 

A: Yes to all your questions on this one. Remember though more is never enough when it comes to filtration. If you go smaller and I’m not too sure how small you mean, then some plants will definitely help in all situation to make your turtles and fish feel more at home and give them some cover in direct sunlight. The larger the filter (more Biocenosis baskets) the better the issuance that if you have a mishap or unforeseen insult you’re covered especially with turtle fungus. All aquatic turtles are subject to shell fungus and a UV light will help keep bacteria count down.

 3) I tried to find the most "old school" cat litter but here in HK, almost every pet store I went to are selling "new age" cat litter that are either scented or made with some "green" materials like corn or paper. However, I've been using AquaClay(http://www.aquaclay.de) in my aquariums for some time and I can get them at wholesale price, if it's not too much trouble for you, would you be so kind and check out their web site and see if they can be used for substitute of cat litter?

 A: I looked it up and it sounds promising enough. I would still add the Laterite for the aid of bacterial growth acceleration. However, is it cost effective?  The pore-water and permeability sites may be too large for it to be considered “non-clogging” in the long run for pond applications. Cat litter will not allow for dirt and detritus to penetrate to any depth to stop or hinder biological activity from taking place, food for thought? 

 4) Other than keeping turtles, I also breed crystal red shrimps, South American dwarf cichlids (both need acidic water), and crayfish, if it's possible to scale down the system, would it be possible to use it in our sumps? My plan for the new breeding house that I recently got would be using a lot of 4' racks which I can put 6 2' tanks on each rack with a 4' sump at the bottom, do you think the anoxic filtration system would work on the 4'x2'x2' sumps?

 A: Yes you can use it in a sump; they have been doing that in the UK and in Italy now with some success. In other words they like it! Using Biocenosis baskets as a filter for aquariums is nothing new and most like it because they don’t have to worry about clogging of their filters. A sump underneath the tank hidden from sight is cheaper than buying an expensive canister filter, too. Just buy a hang on the back overflow with built in prefilter and that’s it, a hobbyist pump will do for returning the water to the tank.

Yes times are changing and we now have to change our ways of thinking to! Good for Cichlid tanks were these animals like to dig or are very touchy about water quality. 

 5) One last question. If you think it is possible to use the system in our sumps, since invertebrates are very sensitive to water quality, mainly copper. Do you think the Laterite in the baskets will be harmful to them? 

 A: Copper is not a significant trace-element in Laterite. Therefore invertebrates like Mollusk, Snails, and copepods and so on will not be affected by its copper content. I have already experimented with such and find it does no harm to them or their breeding habits. However, some hobbyists have reported the eradication of snails by using the Anoxic filtration system, but I myself have not found this anecdotal information to be true.

 Again Dr. Novak, thank you so much for your time and I'm excited to implement your system into my pond and tanks!


 Sent from my iPhone

This Red-eared slider is one of the most common water turtles you can buy here in the U.S.. It’s also susceptible to getting fungus and even a contorted shell if it does not have good water quality and proper food. Anoxic filters make excellent turtle filters because they are cheep and can be integrated with the pond very easily and give the animals the water quality they need. Photo from internet Archives.