help me decide which tank to buy!

[severum mama]

My 2.5 gallon pico reef is going well, for the most part. However, I am having one major issue with it. I cannot keep the front acrylic clean and it is driving me nuts!!!:mad2: I've tried an acrylic scrubber pad and it just isn't working, I have to scrub the heck out of it to the point where I'm afraid of scratching the tank. So, I've been tossing around the idea of moving everything into a glass tank, which I have found is much easier to clean. I can't decide if I should buy a 2.5 gallon tank, or a 5.5 gallon. I'd prefer the 5.5 gallon, but I only have 18W PC lighting the the tank, and there is no way I can afford an upgrade. Would 18W be enough for a 5.5, or should I just stick with the 2.5?

edit- I forgot to mention that all I have in the tank are soft corals. I have clove polyps, neon green clove polyps, green star polyps, green hairy mushroom, purple mushrooms, and zoo's, plus my yellow clown goby. Also, please advise me on whether or not to keep the sand. It's not very old; the tank was started on 4/14. Thanks!!!

[Fishieness]

bigger is ALWAYS better in this hobby. lol.
but with only 18 watts of PC, you might find that your corals look better in the 2.5. they would survive and do well in the 5.5, but they woudl probably do bette rin the 2.5. what about jsut adding another 18 watts of PC? your LFS might even have an extra ballast laying around that they could give or sell to you cheap. i know oceanic gave the one i work at a few ballasts for the biocube if any failed, perhaps they will sell you one of those, then you can just buy a bulb?

[severum mama]

problem is, I really have no extra money. I'll keep thinking about it, maybe put it off for a while.

[severum mama]

Thanks for the input fishieness, and everyone in chat!:)

I bought the 5.5, and if the corals start to look bad then I will just save for another light fixture. So far the 18W light looks pretty good over the tank.

No pics yet, tank is cloudy.