Quote Originally Posted by irydyum
If I'm not mistaken pH is correlated to temperature.
I believe that's only for ph pens... something to do with the electrode function. The aquarium ph test kits don't come with a temperature-adjustment chart like the ph pen's calibrating solution does, so I'm assuming the temperature chart isn't necessary, as proper ph in an aquarium is critical.

Looks like a ph issue to me also, but I'm not a hydro guy either.

Keep in mind, with ph out of range, it will lock-out nutrients. But low ph locks-out different nutrients than high ph, so appearances may vary. Res temps and schedules could also be candidates too.

Best to listen to the hydro guys that have shown success though. :thumbsup: