Quote Originally Posted by urbanfarmer
It could be anything, but I don't think it's the fish.

What discoloration or deformities are you noticing on the plants? How are your water parameters such as ammonia, nitrite, and nitrate? What's the pH? What's the temperature and sunlight like for the plants? What plants are you growing? etc, etc etc...
Stucco, am I correct... is this your underground tank..?
If it is that tank....

'maybe' the concrete is effecting the water...?

'maybe' you have more of a smell because the surface of the water, in the tank isn't exposed to as much air ?
( guessing there aren't too many breezes across the water's surface 'underground' )

'maybe' the system's water doesn't have 'as high' an oxygen level as your 'other' systems ?