1 live rock houses beneficial bacteria that helps convert toxic fish waste from ammonia>nitrite>nitrate. without this bacteria, your livestock would die quickly.
2.a frag tank is a "propogation" tank, it allows you to grow out corals and watch closely for problems, these tanks are usually designed specifically for the corals and may house only inverts or a single fish or two, it also helps to keep the corals from getting damaged or nipped.
3. most sw
fish do eat pellets, but there are quite a few that need more than just pellets (frozen, freeze-dried, etc) its usually a general rule of thumb that you should vary the diet as much as possible. also certain sw
fish have requirements.
... Total Dissolved Solids. although they don't necessarily cause problems in a fw
tank, they def can be quite a headache in sw
tanks. using any water with a high TDS
count can have various effects, including high algae growth, cyano
outbreaks, cloudy water, etc. ultimately theres a lot of "stuff" in our tap water that shouldn't be there naturally. (its usually to benefit humans). an RO
unit will remove these unwanted TDS
in water. making it 100% pure h2o. although you may think the units are expensive, keep in mind that they usually pay for themselves in the first year or two. the price of equivalent water from a LFS
or other store is usually pretty expensive.