250 or 400 hps?

I have pretty much the same size space you have and I'll be picking up a 400w dimmable. My temps right now with CFL's are at 60°F (winter time) so I should be able to run it at the full 400w during these months. For the warmer months I'll be dimming it down to 200W/300w. I'm looking at the ReVolt systems that are dimmable to 50%/75% (200w/300w) power.

So the ballast i have for the 250 wont power an HPS bulb?

Believe it or not my 400whps is not very hot. I"ve got a heater running in there about 18hrs a day. This is good as fot the room is very humid and this dry's the room out. So without the heater I am in the 40-50% range and the temps are 65'. If I pay attention to the heater(check it every so often) the temps are 75-80' and the humidity about 25%. For me today is the 15th day of flower and the tops are starting to develop colas. You can see the cola sprouting all over the stem, little white hairs everwhere!

A 250 is a waste of money.....go 400. The only thing a 250 is good for is for very very small spaces, and using to start getting clones used to bigger lights from the cfls they start in. A 250 will give you stretchy and small, fluffy buds IMO. I'd even go with a 430 sun agro if they still make them.....mine is 15 yrs old, just a backup. Remember, if you get a HPS, you'll need to get a MH conversion bulb for veg that runs on the ballast of the HPS, and it has less lumens, so a 250 conversion bulb for veg will be too little. JMO.

kvnbeach said:

So the ballast i have for the 250 wont power an HPS bulb?

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The ballast you have will run both bulbs, MH and HPS (all ballasts do).

KushisSweet said:

That's why you use digital compatible bulbs. Digilux for the win! Besides using any hps weakens performance overtime, resupply every 6-10 months!

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I didn't say don't use digital, I said don't use DIMMABLE!

DIMMABLE BALLASTS LOWER THE LIFE EXPECTANCY OF YOUR BULB CONSIDERABLY (more than normally expected) AND CAN LEAD TO THE BULB EXPLODING, DUE TO THE BULB NOT BEING DESIGNED TO BE DIMMED REGARDLESS OF WHAT THE BALLAST IS CAPABLE OF.

Digilux bulbs are designed to used with digital ballasts because of the quicker start up time (they shouldn't blow upon initial surge). There isn't a bulb yet that is designed to be dimmed, regardless of what your ballast can do.

Hope that clears things up.