I've tried it. Got excellent growth with the liquid for houseplants, $2
squeeze bottle.

It won't harm your fish if you don't add too much. If you add too much,
the fish will get bloody welts and die.

Don't add more than 2 drops at a time in a 10 gallon tank. Eventually
the plants use it up and you have to put a couple of more drops, maybe in
a week or two - depends on how quickly your plants use it up. Monitor
the ammonia and nitrate levels.

Floating fast growth plants seem to love it and grow like crazy.