mh ballast

[rayyue]

i'm going to buy a new 400w mh ballast, but not decide to buy tar or electronic, what's the main different between them, which one you guys is sugest if the price is not the main factor, thanks

[jws444]

If price is not a huge concern, then the heat issue would be the biggest difference you'll notice between a tar and electronic. Secondary, would be noise. Tar ballasts have a hum, whereas electronic ballasts are dead silient. Thirdly, I think the electronic ballasts are a bit more stable and less prone to 'off cycles'. I'm running 400 watt tars myself and haven't had any problems with it shutting off though.

[rickjames]

A big difference is output. Have you checked out Sanjay Joshi's lighting tests? His test are fairly reputable, his site is: http://www.reeflightinginfo.arvixe.com. Just use the search performance data for 400W, or read his articles.

The most light output comes from the 400W HQI ballasts, which are actually a High pressure sodium 430W ballast. You can buy them from PFO or your local hydrophonics store.