Heat problems

What's the best way to deal with heat? I added my 400watt hps yesterday and my cab shot up to 90. The ballast is outside so it's all the light that's making the heat. So what's the everyone's opinion? Cool tube or new exhaust fan? The fan I have in there now I think is under 100cfm it's more like 60 probably. So I found a 265cfm dayton at my local hydro shop I'm thinking of getting. My cab is 4x4x2 so that fan would exhaust the air over 8 times a minute. The new fan would be about half as expensive as getting a cool tube properly set up. Advice??

anyone...please....hello........

From all I've read you definately need more aireflow than your current fan. 265cfm seems to be the "norm" for 400 watt systems.

You can pick up a 265cfm can fan from ebay. Search for air booster fans or duct fan. As far as building a cooltube, you can get the fan for 30(ebay), a candle vase for 9(michaels, ac moore, basically a good craft store, just check the candle section). Add some ducting and supplies from home depot or lowes or any hardware store, for around 30 bucks and voila you have everything you need to make a nice cooltube that will dramatically lower the temps and can help save you some money. Hope this helps- Diz:rasta: