Keep an eye on the pond readings...
Do a very large w/c 80% at least then test again,you have excessive ammonia/nitrite,give it a good gravel vac also,you need to get these down to close as you can to zero.Another test, results coming.
P/H 8.2
Ammonia-0.50 ppm (i added some plant food as they were looking a bit yellowy)
Nitrite-0.25 ppm (i guess this is the filter degrading it into nitrite)
Nitrate-
Actually, many fertilisers which supply "nitrate" will give an ammonia reading on some water tests.. this is why I do not recommend fertiliser dosing in aquaria which are not stable. Also irregular dosing will cause more problems with plants than it would fix, so it is best to either dose all the time or never at all.Still do the w/c,its not suppose to show any in the tank...