400 watt MH DIY

[Aquarium_Medics]

A friend of mine was removing some light standards for an aviation fuel station which had a 400 watt sodium light fixture lighting the area. He grabbed the Fixture off the pole and gave iit to me thinking i could use it for my 55 gal reef build. I know i have to disconnect the ignitor for MH bulbs, however, I'm wondering if 400 watts would be too much for a 55 gal, and 2) if 400 is too much could i use a lower wattage bulb in it??

Thanks in advance for any help.

[Delphinus]

I've never heard of removing the ignitor for halides. A few years back there was an "HQI" 400w MH ballast which was just a SonAgro ballast (430w) for sodiums. Same everything, just run a halide instead of a sodium.

In fact it might work better than a 400w probe start ballast since most halide lamps in the hobby are meant for pulse start. Probe start ballasts do work (mostly) but are hard on the lamps (shorter lifespans usually).

400w is an awful lot of light for a 55g. You will have major heat issues to content with. Not saying it can't be done but it is definitely overkill.

Unfortunately no you cannot mix and match wattages with lamps and ballasts.

[Aquarium_Medics]

Kind of thought it was over kill. Thanks for your reply. I have researched about removing the ignitor so it will run MH, didn't know that you couldn't switch wattages though as i thought it would be the same as using different watt light bulbs in your home.

[Delphinus]

The way it was explained to me, the ballast is like a sort of a brake. As the arc tube in the lamp heats up, it offers less and less resistance, so the ballast is used to govern the electricity flowing to the lamp. So lamps and ballasts need to be paired to one another..