polished aluminum reflectors?
is it just the plants on the ends, on the bottom, what?
i find pink bulbs (i think your full spectrum) to be horrible for plants so you may only be getting like 1.5 bulbs output. bluer bulbs penetrate better so you might try switching that out with a 10,000k instead. i know it sounds horrible and that might not be "the right color" but par is par and many 10000k bulbs put it out well.
moss should do well without bright light usually so, i don't think lighting is your problem with them... idk.
i could see where your water portion and plants near the corners would have their light blocked if you still have the light set up like this...
you may be able to take off those end pieces (what are they, more lights?) and put bends in your legs on the other fixture to hold it up higher like it is. it might help spread the light out.
i don't think 4 bulbs would be necessary personally, but 36" bulbs might be.
this plant...

looks like it could be hc. if it is you can expect it not to do so well unless all parameters are accounted for... not just light. you may even find co2 injection to be a necessity, idk. once i have enough i'll test that myself. apparently d. walstad has had success with it lately without co2 injection so that breaks that train of thought... if it continues.
your other plant in the water could use some root tabs if you haven't been using them. that might help tremendously.
for your moss (and best results with your other plants) you'll want to mist with clean (as in r/o, rain or distilled) water... periodically at the very least. for your aquatic plants you basically want the total opposite. you'll need all the minerals and ferts necessary to be there... at all times.
if you're going to go with a 4 bulb t5ho setup you might as well just shoot for hanging metal halide pendants above the tank. i think either option will be a little bright for your tree frogs though. at least with the mh you'll definitely have enough light and if it needs subduing you can just raise the fixture up some. just a thought.
one thing you can do to test whether it's your lighting or not is to add a couple cfl's directed right where the problems are. if that doesn't help it's probably not lighting and you don't have to waste a couple hundred dollars on a new fixture to fix a problem that doesn't exist.
as for the broms, i don't know. aaron might know better what they need. i have seen people who swear by bright light to keep the colors vivid and i've seen others who say it's not necessary and not right to do to your nocturnal creatures. i might agree with the latter of the 2 except i haven't grown any broms, lol.
basically, my point is make sure you're doing everything else right before you assume it's your lights that are the problem. i wouldn't want to throw away the money for such a fixture.
a decent place to find bright lights on the cheap (that came with recommendations)...
fish need it;lights; food;Sponge.
another point to ponder... don't know if it's applicable, but... watering at night. seems to be a bad idea from what i've been reading cause it can cause temp drops that last longer and can be detrimental to the plants. maybe i've just been reading too much, idk, lol.
hmm... looked again and it definitely looks like mineral spots on your ???schefflera??? here...
so, yeah... i'd use clean water for misting, fert my water section and use root tabs... give that a month or 2 and see how that works out... then maybe add a cfl in a clamp or desk lamp in my problem areas and THEN consider another brighter lamp.
i'd hate to see you spend all that money for nothing.