Holding tanks for nitrite to nitrate bacteria..

[Rick Welland]

. A idea came to me this afternoon. Had always intended to solar pump the fish pond water up the hill to 3 holding tanks and then circulate it thru the growing trays back to the ponds. Thought was why not fill the bottom 2 feet with 1" river gravel and let the bacteria do its thing all over the surfaces of the gravel- would that serve as a constructed wetland to take care of the nitrite to nitrate thing? Or perhaps construct a channel between the tanks and the trays filled with gravel and grow some watercress a la Will Allen...Just a thought...

[TCLynx]

Well it's more than just nitrite to nitrate but first you need ammonia to nitrite.  You could do the holding tanks but I would recommend heavy aeration to make sure you are not causing anaerobic decomposition that can, if unchecked, cause some bad things.  However, Having extra holding tanks might not really buy you a whole lot if it means you then need to supply extra aeration.

[RupertofOZ]

Yep... having submerged gravel in a tank can be a bad idea...

 

It can end up trapping the solids... and becoming a fastering mess... requiring regular cleaning/maintenance...

 

If you're going to run water through a tank with some gravel... then you might as well fill it with gravel... throw some plants in .. (watercress will do).... add soem worms... and presto, a productive grow bed...

[Rick Welland]

Thanks for the good advice..sounds like Will Allens constructed wetlands with water flowing thru and watercress doing its thing with the baddies is a better way to go. Will need one of your test kits soon as the next friend is traveling south. Very curious to test the water more in the large ponds. Is a reading from a pH test strip for the human body accurate? Tested two areas in the ponds and both came up 6.5. Have lots of different algae growth in the shallows. We have some floating small rounded green leaves which is maybe duckweed. Possible for someone to post a closeup pic of duckweed? So if we have various greens growing in the pond water, algae in the water, and what appear to be happy fish does that indicate nature is doing its thing re balance.? Have for some years assumed that green plants growing, algae and fish swimming around meant a 'working' pond system. A lot that we don't know about what constitutes a balanced situation etc..Thanks again for helping us keep to the 'straight and narrow' of AP...

[TCLynx]

Happy fish and growing plants is a good sign of some sort of balance, how adding your aquaponics will affect that balance or how that already balanced system will work with aquaponics is yet to be discovered.