1. what doesw FOWLR mean?
Fish Only With Live Rock
2. why must u use RO/DI water?
You don't HAVE to IME...but other will tell you that you do. My tap water is <100ppm TDS, I got away with it for two years in my reef. I needed to switch to RO/DI when I upgraded my lighting from CF to MH. A lot of tap water just has high levels of dissolved solids which can lead to serious algae issues in high-light tanks. If its a low-light FOWLR tank, it may not be as much of an issue.
3. how does an RO/DI unit work?
Depending on the unit, it will have 3-5 stages of filtration. Mine has two sediment filters, a carbon block filter, then the RO and the DI. The reverse-osmosis filter basically is a mechanical filter at the molecular level. It removed dissolved solids. The deionization resin uses a polarized resin to remove whatever is left, mostly polarized ions too small to get caught by the RO membrane.
4. why can't u use conditioned tap water?
see answer 2
5. what are all the tests must do for SW?
For FOWLR, after the basic cycling testing of ammonia, nitrite, nitrate, you're good with nitrate, KH and calcium. For reef, you want to keep tabs on pH, KH, Calcium and magnesium for basics, some people test for a lot more.
6. is live reef same or different from live rock? how?
Reef implies living coral in the tank. Live rock is just rock that holds tons of beneficial bacteria and microorganisms that basically act as the biological filter for the tank.
7. what is most common issues in a new start up?
If you do your research and follow the correct steps, cycling should be the only real issue, apart from possibly treating illness in QT.
8. what are common issues in an established set up?
I myself have not had any real issues in the three years or so my reef has been running. Minor algae, and some equipment issues (crappy skimmer, crappy lighting) were the only real problems.
9. what are most common diseases?
Ich is probably the most common problem.
10. what are most common mistakes a newbie makes?
Rushing things can cause big problems down the road. Skimping on equipment can bite you in the rear as well. "The only things that happen fast in a reef tank are disasters."
11. what brand salt is best to use? which is most economical?
This varies a lot by personal opinion and experience. I use Reef Crystals, others swear by Oceanic or any number of other brands.
12. why does one need a sump vs just using hob's?
You don't NEED a sump, its just a popular option. It adds water volume (and therefore stability), you can include a refugium in a lot of cases, and it gives a good place to hide equipment.
13. what is a refugium & its purpose?
A fuge is an area that provides refuge (hence the name) for small organisms that might otherwise get eaten in the display tank. Good place to grow macroalgae for nutrient export, a place for a deep sand bed for denitrification, to grow out pods to support the DT population.
14. what does wet/dry filter mean, how does it work?
Wet/dry is another method of biological filtration, not used to often any more in SW tanks, as the liverock does the same job.
15. can u mix live rock, live reef & coral together?
A "live reef" is basically a FOWLR tank with better lights and coral in it...so, yes.
16. will I ever have the nerve to start one up??
that one's up to you.
thks all for your time.