As I recall, salinity is affected by temperature, although I'm not sure what the factor of the relationship is. You might want to keep this in mind.

it does indeed, but i think for my method and only having a 2-3 degree (80-82) swing i dont think its really going to factor in too much. the whole basis behind my method is to sustain a constant temperature, not allow it to climb very high then try to bring it down. by experimenting i have found the ideals for my particular situation. never more than 82 and thats with all the lights 'a blazin :biggrin: