Backyard Aquaponics
A place to discuss aquaponics

dear friends

I have two very straight forward question regarding Mineralization tank (thank contains fish waste from the swirl filter)

1- How long shall I keep the waste water inside the Mineralization tank aerated and moving?? is it until I get zero Ammonia and Nitrite reading??

2- if I noticed the pH inside the Mineralization tank is down bellow 6.5 (since the bacteria is working rapidly) shall be adding pH buffering agents inside as well to keep my bacteria from dying


thank you all in advance

1. Most people run a batch mineralizer that they allow to settle and then draw off some of the liquid portion daily or at some regular interval (which they add back in to the plant portion of the system). Since your adding solids regularly, you will have solids in varying states of breakdown so really your goal is to keep these solids in the mineralizer for further mineralization but remove the liquids which contain dissolved solids like ions. Everything probably will not break down but most will be broken down within a month. I've seen annual cleanings of undigested sludge recommended but I've also seen others who haven't cleaned out their mineralizer at all - just figure what works for you.

Getting good breakdown is dependent on having all the right inputs in the right amounts and you'll probably find that you need to regularly add some form of carbohydrate to the mineralizer, if you aren't already doing this. This has to do with the carbon to nitrogen ratio, similar to what you'd play with when trying to get your compost going. Some carbohydrates work better than others because not all sugars can be broken down by all bacteria. I've seen corn starch mentioned and I know that regular table sugar should work fine as well but some other carbs might not. You're trying to grow a different type of bacteria from what you would grow in your media beds and these bacteria prefer a higher carbon to nitrogen ratio.

2. The bacteria should be OK (by this I mean, still processing the solids) down to a pH of about 5.5 but you can buffer the pH up if you want and add nutrients in the process, like potassium or calcium, similar to what you'd do for your aquaponics system. Bringing in new solids should help some as well. The bacteria do like a higher pH (probably in the 7.5 to 8.5 range would be good) and will probably work and multiply faster under better conditions which would include pH and temp.