The obvious reason, to me, why it wouldn't work terribly well is that, in order to provide enough light for growth of outdoor plant seedlings, the fluorescent canopy would normally be sitting directly on top of the seed tray, once germination has taken place. (The seedlings may even touch the fluorescent bulbs; it doesn't harm them, since the bulbs are not hot.) One would then raise the canopy upwards as the seedlings grow, simply to give them the vertical space they need. And nothing is more important in growth of seedlings than adequate light. Unless you do some modifications to your canopy, I'd guess it is designed, as per norm, to sit on top of the aquarium, right? You'd either have to raise the trays, or lower a shorter set of lights down into the aquarium in order to make an effective seed-starting table out of it. So, I'd question using the aquarium for growing.... but it could be useful for germination, if you set a tray (or trays, stacked with some space in between) in it, and kept it covered to preserve high humidity. Once the seeds germinated though, you'd have to provide light (but not until then). Hope this helps, assuming I'm interpreting your set-up correctly.

IMO the biggest problem with the Under Gravel Filters (UGF's)is after a few years the plates gunk up on the bottom and need to be torn down and cleaned. If not a bacterial bloom is usually the case. There are still a number of people who use them and claim they have no troubles. There was a post here a while back, I'd say august-september, the post was an opinion on UGF's. The poster deffended his UGF stating it never had problems. Then later in the thread stated that all that was done besides good vacuuming was adding a liquid water clarifyer to clear the water when it clouded up. To me that is a problem. Anaerobic bacteria grows on almost any surface submerged in the water (gravel,decor,rocks,etc.) where it is dark and has a little water flow. The only problem with just using a UGF wont give you much surface area that is also dark, has good flow and air for aerobic bacteria to grow. The inside of an external filter (excluding canisters without a Bio-wheel) is a great place for this. It is often said that when there is an unbalance of aerobic and anaerobic bacterias that the bacteria blooms occur. This clouds water, poses possible infection to fish and could all together crash the biofilter. At least thats the way I understand it. IME using UGF's solely and along with hang on the tank filters is that the water would get somewhat cloudy after a while. I never new at that time to remove the plates once a year to clean them. It seems that since not using them I have had cleaner water then before. This could also be because todays filters are better quality then ones of old. With all this said, UGF is better than no filtration at all. I wouldn't use one ever again because of the maintainance involved compared to an external filter. To add they are not compatible with live plants either, rooting problems.

Squirrel-- I think the test sets you are refering to are the old pH dip-strips with the pH up and down additives. You are correct they where crap. Battleing pH with those powders was temporary, especially trying to bring high pH down. Just monitoring ammonia and nitrite is important because it can be found in tap water. Some water treatment facilities even add them in their efforts to make drinking water "safe". As far as fishkeeping not science, I find it more a science hobby now than ever. I had the same opinion as you when I lived in a different part of the state, never a problem and never tested. When I moved I couldnt keep from killing a fish within 2 weeks. The well water I have now was a little different to say the least. I purchased a test set and found my cycle would stall. For whatever reason my ammonia would spike and stay, never lowering. I tried every useless product the petstores would reccomend, nothing. I read books and magazines, the books where a little out-dated and the magazines offered newer info, but not as quickly as I needed it. Most research from then started with a search on the net. I just lurked on boards,and still do,and found consistancies with advise from different ones. Anyway within 2 weeks of good advise my aquarium cycled and have started several others. I am still learning, and find I learn alot by trying to answer questions. So in my case and more often than not, fishkeeping is a science- ecology, biology, and mostly chemistry, not to mention botany. For years I thought was just an art, but chemistry taught me otherwise

If your pleco is the P. Gibbiceps species then I've had them get up to 14"+. No matter when you change to sand out it's going to cause a major re-cycling in the tank. When you do it take the fish out then stir the sand. All the "dirt" that floats up out of it is wahat you want to save some of. I'd try to keep as much of that water as possible. At least half to refill the tank with. It'll look bad for a while but hopefully you'll have enough bacteria in it to keep the take from going thru a complete cycle. Also have ammonia and nitrite test kits on hand and check those daily. If you see either getting high enough to be dangerous or starting to make the fish uncomfortable then change some of the water in the tank but NO cleaning. You'll take out more of the bacteria you are trying to cultivate. Just remove some water and refill. Be sure to check the temp and use dechlorinator.That should keep any amm/nitrites at a level the fish can survive in temporarily until everything gets back to good levels. Lisa