Hey CM thanks for the holler its neat to see new pico builds. someone is getting hooked, about to pay lol
for sure reefcrystals are fine. there is lots of roar about them at times online, instant ocean too for its cheapness, but pico reefers have absolutely no trouble with any salt brand made.. any of them. what Martiza does w IO is enviable
Right now we could go into my old pico, drain it empty, and come back 20 mins later (sat in air for 20 mins, in threads) with a full wc of any salt brand on the market and do a 100% water change and it would be fine in an hour.
param differences wont kill a pico, and I only do full changes not small percent ones. picos can be made to run like the tidal zone where there is good current, good export etc and the corals rise to the occasion or calmer settings work too... after all mines just an airstone moving water around, nothing intense.
we make 1 gallon reefs run long term, 3 is easy, -but- that means easy in terms of pico reef work that doesn't mean a 40 isn't more stable, it is.
Salinity control is the only real challenge for smaller tanks, past that they are easier to run than larger tanks because its easy to control nutrients w water changes, and because we can take the tanks apart for cleaning as needed. topoff is the major challenge, and so the larger picos like 3-6 gallon are more common as keepers experiment with various salt control levels/
here is the longest charted 3 gallon we have online, and by the way, the refugium is not critical to the setup. the exact same lifespan, and loss due to sandbed clogging/cyano takeover would've been the same with or without the little refugium (neat, but not a key aspect of design) solely due to max lifespan for uncleaned pico sandbeds.
this proves that with only light feeding, and 50% weekly water changes and no dosing, you can take an sps pico 3 gallons out to 3 yrs:
http://www.nano-reef.com/topic/180570-el-fabs-simple-guide-to-pico-tanks/
Maritza the vase reef is the maker of that wonderful setup in the article I appreciated working MVR