I agree. Unless you have a very deep tank the added heat and electrical usage of 400w doesn't justify a marginal (if any) increase in PAR. In fact, with some setups a good 250W system will outperform a 400w system.

Well that is why i went from DE to a mogul again after getting bulbs megachromes at 115 each and breakin them twice not impressed. now i run mogul's if the DE 250's and the 400's well like the 150's i would have kept them . but the way they are you wont see me going back to them ever again...

There are practically no choices or sources for 400w DE bulbs.

You need to buy electronic ballasts or use tar HQI ballasts @ 5.5 amps each.

Maybe you could upgrade your current halide reflectors to Lumenarcs for an upgrade instead of going 400w DE.

heh, well i like the hamilton 14ks... my experience with those are on the 250W DEs so far, so those are the bulbs i'd use.

so right now the ballasts i have are ansi m135. should i be considering swapping those out for something else? will something else run the 400W DEs better?

what ballasts are you talking about jack?

I haven't heard about a Hamilton 400w DE.

Just dont do it lol....