Your plate coral & clam look good.

I certainly understand your frustration... makes me mad that "pros" take advantage of people like that. On the other hand, it's very good to hear that you are now set on doing a lot of research. I would suggest that you don't buy anything but that RO/DI unit until you have done a lot of research.

My concern is that it seems like you are adding things to the tank (top-off water, additives) because someone told you to without telling you why.

If you study hard for the rest of this weekend you can get the fundamental basics at least. Keep at it & you'll start becoming more confident and knowledgeable every week.

Here are a couple of links with a ton of articles. I'd highly suggest that you read, read, and read more until your eyes bleed :blink

http://www.reefs.org/phpBB2/viewtopic.php?t=33928

http://reefkeeping.com/issues/subject/chemistry.php

In the mean time, if you have test kits, do tests on each of the tanks for the following and maybe we can help you to avoid disaster for now:

- Salinity or Specific Gravity (you might have a swing arm hydrometer for this)
- Ammonia
- Nitrite
- Nitrate
- Calcium
- Alkalinity (dKH)
- pH
- Water Temperature

If you take some pictures and post them of the equipment that each tank uses, that would help (i.e. protein skimmers, filtration).
What kind of salt are you using and how often do you do water changes?
Do you have many snails or hermit crabs?

Mark