I’m preparing to start my second grow. My first grow was a seed I sprouted (possibly Bubblegum but not sure). It all went fairly well for a NOOB with a DIY setup. After sprouting in a peat disc I planted in FFOF that I mixed some worm castings in. I watered with plain dechlorinated tap water and every week or so watered with water I siphoned from my freshwater aquariums I also sprinkled ground eggshells occasionally. A couple of times, during flowering, I soaked it with “tea” from worm castings. (I have a worm farm to feed my axolotyl and a large fish.
After doing a lot of reading here, My question is:
Is there too much nitrogen in the aquarium waste water for use during the flower stage? (The reason for the water changes in the aquarium is to lower Nitrate levels.) and is the worm castings tea good for both veg and flower stages of the grow?
@Skydiver I have read a lot of your stuff and would like your, and everyone’s advice
Thanks!
Mostly N in the castings. For flower I’d be looking more towards fruit bat guano as it has higher percentages of P and K than either worm castings or insect bat guano.
Fruit bat guano hmmm 
Thank you! Never would have thought of That!
You have to be careful with fishtank water. Some larger fish excrete a lot of ammonia and
that’s not good for the soil biome and plant. Just be mindful of the amount of fish piss in the tank water. Also pH the fish water before you feed it to the soil.
Thanks @PhillyRock My ammonia levels are always nil as I have good beneficial bacteria filtration, however my pH is a little alkaline. Most tanks range from 7 to 7.6. I thought with live soil the pH going in wasn’t such an issue, but next grow I will be aware of this and take only water from the tanks with no higher than a neutral pH. Thanks again for the tips! 
Check out potentponics, he has a podcast all based on aquaponics/growing with the fishes.
From what I’ve read/listened too the microbes in the fish waste are the true hero of aquaponics.
Yes living soil will buffer the ph but you don’t want to make it do more work than is necessary.
Spikes in pH aren’t good for living soil neither. Just being in the Ballpark of neutral is fine.
@AAA Thanks so much!
@PhillyRock thanks for the help!