Feeling Cool Under The Scorching Sun

Today is the first day I left my metal halide lamp running. its been running for 7 hours now and thats the approx. photo period that i'd expose my tank to. Although there's nothing in the tank, I kept it on to test and ensure that the chiller is able to still do its job despite the extreme heat radiated by the lamp. Water temperature is now sub 27degC. Lovely. Rocks later today? :) let's see how it goes.