Backyard Aquaponics
A place to discuss aquaponics

Nice fruit there bf....didn't eb offer you some of his fish when you spun him the yarn nearly being dudded by an unlicenced fishing bloke

Not very AP of him

thanks for the replies guys. glad to see you all following along.

i have to admit i didn't really believe that worms could live in water until i saw it myself. it just doesn't seem right.

I have given him some IBC's instead... Better than fish.

shhh don't tell anyone or johnny will know who stole his ibc's. haha.

don't worry johnny i left you the blue one.

actually i was eying off some of eb's silver perch giants to use as broodstock. apparently one of them was "behaving quite strangely last summer".

Johnnie's got the Barrelponics system I'm sure he is happy... Well he will have it soon..

hi all,

thought i would put up a pic of one of my tanks.

for the last 3 months i have had the growbeds bare, as i have simply been to busy. i havent had the chance to check nitrate levels as my reagent leaked.

the interesting thing is the lack of algae. i would have thought that my nitrates would be right up and feeding an algal bloom. DO levels are high in the tank. there is biofilm covering most surfaces in the tank. along the rim where the water level begins there is a patch of algae.

my thinking is that either the nitrates are being consumed by the bacteria itself or the algae is being consumed by zooplankton which i added to the tank.

i got thinking after someone in the aquacultural industry told me that an aquarium shop was running huge biofilters with no plant but nitrate levels didn't rise. i asked if they were doing water changes to keep the nitrates down and he was convinced they didn't. i don't know how true this is but perhaps someone here who knows about the chemistry could chime in.

anyhow heres a couple pics.

Wow man, your water is so clear.... definitely no algal bloom going on there...

Are you sure there's water in there?

your onto me Xzorby,

i've actually genetically engineered a new species of birdfish. nutrient rich air is pumped into the growbeds to grow the plants.

Nitrates can off-gas in an anaerobic environment. By definintion, we all have anaerobic micro-environments. Some of us are using larger anaerobic filtration to get rid of excess nitrate. I, for one. Les is experimenting with it.

well that would makes sense as the way the water is circulating would produce "dead spots" in the tank.

to what extent can the nitrates be off gassed? i mean could all nitrates be off gassed if there are enough anaerobic spots? or are only certain types of nitrates able to be off gassed? i gather this is a new mode of thought as there's no mention of it in my aquaculture books.

thanks Janet.

janet and the RSG have it sorted. One of the tricks is that you need anoxic (just before anerobic) conditions.

Here you go...
http://www.backyardaquaponics.com/forum ... php?t=1523

I was struggling horribly with high nitrates--up over 1000 at one point. Water changes got me down to 300-400. Struggle struggle. I installed my RSG filter, still not doing much, but down to 150. Corrected my pH, and Bam! Nitrates dropped from 150 to 5 in 24 hours. At this point, I am easily keeping nitrate between 10 and 40. This week I have a nitrate of 5. Hmm, time to choke back the RSG filter a bit. Les has just constructed an RSG filter in an independent set-up, and will no doubt do more scientific testing. Marine aquariums are also using the concept that anaerobic bacteria will off-gas nitrates.

thanks for the info Janet.

the interesting thing about one of these bio-filter's he was making was its design. it was a large box with many segments. the water would pass through the bottom of one segment and flow over the top of another. there was a section for collection of solids in the first segment. it would make sense if the bio-filter was designed for anaerobic conditions as it wasn't a standard bio-filter.

is this well known in industry Janet?