Depends what type of ballast it is.. there should be a lable stating what is powered.. oh wait if it is a fish ballast they whould have scratched that info off
ok your plan sounds like it will be cool.. one chunk of advice.. if it isn;t much more for a 250 watt set up.. go with two 250 watts I have 175 and it only has enuf light rather high up.. thats why I am upgrading to 250's.
on a 6 foot tank what you could also do if you go with 250's is mount the bulbs a little higher and mount them 1.5 foot in from the outside.. this will give you a faily good coverage and you most likely won't need anything in the middle. 2x2 is a normal coverage from a MG for high intensity but you can light a 3 foot tank with one to fairly good levels..
Steve
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