24watt bulbs in an 18 watt ballast????

[nanonut]

I have the Via Aqua 15 gallon tank with the stock light which are two 18watt 1-7100K daylight and one 12000K actinic. I am going to put one 70 watt MH fixture on my tank, so I wanted to keep my stock light fixture, but put two 24watt actinics in it. Is it safe to do this, and has anyone done this??? Am i better off just going with 2X18watts instead???

[Jahkaya]

Check the Ballasts and see what they are rated for. if it is rated for 48 watts, no problem. Better to go with 18 watt bulbs anyway as the 24 watt bulbs may not fire.