Red blotches on pitchers?

[Alvin 415]

Please check out these pics. Does anyone know what these red blotches are? These are under 2 T5 HOs. I do use Osmocote in the pitchers. Thanks!

 

[Whimgrinder]

Only time I have ever seen patches of necrotic tissue like this was when I spritzed dilute Orchid fertilizer into pitchers. So - I would assume this is contact fertilizer burn.

 

[Alvin 415]

Thanks, Whimgrinder.

You know, I did recently also use some Maxsea solution (1/2 tsp per gallon H2O) in some of the pitchers. The problem is I don't know if these blotches appeared before or after the Maxsea. And I can't remember which pitchers got the Maxsea. I should keep a log.