No, you cannot put in 35W bulbs instead of the 65W's. <Ballast won't drive it ... unless you have an expensive load sensing ballast like an Icecap .... the ballast is over $200 by itself, I doubt you'll have that in a $100 fixture! OTOH, there are cheap electronic ballasts out these day, so maybe you Do have a load sensing one? Can't tell unless you take out the ballast & look.>
BUT - get the fixture anyway! You can decrease the light 2 ways:
1. If the 4 fixtures are wired in parallel, you can leave 2 of the bulbs out & it will still light. <These fixtures usually have seperate switches for the 2 banks of light, so you can control each side separately.>
2. If the fixture must have all 4 bulbs to light, you can swap 2 of the bulbs with actinics. The actinics won't "count" as far as plants are concerned, so in effect you would be running only 1/2 the watts.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.