Agreed. I went with root tabs instead of my usual dirt on my sons 20g high set up last night. Before I set it up, I read up and found out that too many tabs will cause an algae outbreak. Since I have a lot of root feeding plants (Crypts,Val, Blyxa), I used 7 "00" osmocote + tabs placed randomly around the tank bottom.
Also, from what I read, placing them too close to the plants will burn the roots. (?)
Agreed. I had a 55 and I jammed it full of O+ plus tabs (every 6 inches...) and could not control algae to save my life. I just tore it down because after 6 months of rampant issues I gave up and redid the whole thing.