Formula 28 Automatic Replenisher
Formula 28 senses the concentration of 28 individual elements, including calcium, strontium, and all trace elements, then automatically adjusts each one to the same concentration found in the sea. The blocks or nuggets dissolve only to replace depleted elements in solution.
Algae growth, bacterial filtration, and skimmers are all heavy users of trace elements. Sea-Lab's computer designed formula maintains natural seawater concentrations in spite of heavy usage, even in large Berlin type systems.
Formula 28 also controls many causes of depressed or drifting pH. The formula contains four alumino-silicate "weathered" buffers, well known to seawater chemists, but exclusive to Sea-Lab in the saltwater aquarium industry.
Saw a few reviews online and as setting up a 40 Gallon mixed reef with no sump decided to try em, had noticed some parameters slowing dropping even with water changes as I added more coral but once I added my first block saw a steady rebuilding of parameter's to almost perfect again, these things work and so far not seen any downside apart I have to import them to Ireland but compared to dosing pumps or reminders to add this liquid or that, I think for a basic reef setup or Nano these are the best option out there for the price and convenience. Try them you wont look back. Regards Andrew