Planted Tank Guru
Join Date: Nov 2009
Location: Missouri united states
I would use the stuff sparingly and sprinkle a small amount per volume of water on glass before capping with dirt/sand or whatever.
Or place small capsules if it is in capsule form, one each near root feeder or group of root feeder's/stem plant's.
The stuff is slow release ,and may take a week or more for protective resin or whatever to begin allowing the fert to dissolve more readily in water.
Stuff is said to feed terrestial plant's for up to six month's but Maybe four month's in my experience submerged in water.
I sprinkled maybe a measured cup full on bottom glass of my 80 gal (four foot long ,21 inches wide) before covering with dirt,peat,catlitter mix ,and Black diamond as a cap.
I think too much can cause issues and maybe even harm root's of delicate plant's but have no proof other than observation's when I used much more.
Hope this helps.