fishgeek said:
i get a bit confused ghere with the use of 'organic'
for me it ws a chemical term meaning based on carbon
so when people suggest organic nitrate does that meanit is produced by the decopostion of a carbon based molecule ?
andrew
People generally use the term 'organic nitrate' to mean Nitrate that has been produced by the breakdown of ammonia produced by fish and other things. As you say, not the correct use of the word really.
If I remember corectly (can't find the paper again!), the scientific paper Tom refers to actually does suggest possible effects of lower concentrations of Nitrate too, related to growth rates in aquaculture.
IMHO, however this may be due to higher nutrient levels relating to higher TDS levels, rather than any possible negative effects of Nitrate in itself.
High TDS has been shown to slow growth rates in koi. Indeed many top koi keepers now use RO water to keep their TDS below 100 as this improves Hi development and growth rates in Koi. Here are two articles written by Mike Snaden, who really knows his stuff with koi keeping
http://www.yumekoi.com/articles/aug_2003.pdf http://www.yumekoi.com/articles/sept_2003.pdf
When I measured the TDS of my cube (where I was running EI up until recently) it revealed a TDS of over 300, which shocked me. Bearing in mind all my tanks use RO water with a TDS in low figures after re-mineralised and my tap water only has a TDS of 135, I believe this has to be due in part at least to fertilisers.
BTW my pond's TDS is only 184 and that runs on tap water!
To counter this I'm cutting the minerals added to new water and upping the water changes to 50% more than once a week.
BTW just in case you're wondering why I'm bothered; the two species of killifish I keep in my cube have both stopped spawning and the algae is doing rather well! It may well have absolutely nothing to do with the fertilisers, but I'm trying to rule that out by halving the doses and seeing what happens. The fish seem happier and the male Aphyosemion bivitattum has coloured up again. Again it could be a coincidence - I am no where near drawing any conclusions. Please also bear in mind that killifish are very sensitive fish that require soft, low TDS water to spawn successfully.