additives?

[doh]

Well, I need to spend another $15 on my dry goods order to get free shipping so I thought I might try some additives. I have a fowlr(look at profile) and never want to get corals, but I do have/want shrimp, crabs, snails, caulerpa, coraline, ect.
Which one would do me the most good?:
-Trace Elements
-Buffer(my PH is stable at 8.4)
-Calcium
-Iodine or Strodium or Molybdenum
-Coral Trace Elements
-Calcium,+Strodium,+Molybdenum,+Iodine Mix
-or just get enough carbon for the next 2 months
Im already getting Iron for my caulerpa
thanks
Jon

 

[artskoi]

You just need to add calcium to get to 320ppm for fish only or 420 for coral.Add buffer to maintain ph 8.2-8.4 and alkalinity around 160-200.Then I do a 10-20% water change every two weeks.Don't complicate things with other additives.I have been there and wasted my time.