is it nessesery to use chemecials with saltwater fish?

Answer 1

Water and salt are both technically chemicals, so yes.

Answer 2

Chemicals, such as....? You should still use a water conditioner if you use tap water to make your saltwater, but not if you use reverse osmosis water (preferred). You can get the RO water at Target and Super WalMart stores for about $0.33 per gallon. Since the RO has some of the beneficial elements (calcium, magnesium) removed, you can get something to replace this (I use OsmoPrep by Kent). If your pH isn't 8.2-8.4, you'll need something to raise it, and here I use kalkwasser. Beyond these, everything needed for a basic tank should be in the salt mix. The best way to "supplement" the minerals used by the organisms in the tank is weelky water changes.

You should, however invest in some "chemicals" to test your tank water for pH, ammonia, nitrite, and nitrate, since all of these affect the wellbeing of your fish and inverts. I gave the range for pH above, but your ammonia and nitrite should be 0 (or close to it if the tank is new), and the nitrate should be as low as possible, definitely below 20, but even lower is better.

Answer 3

No. Just like any tank, have the water tested before putting fish in. If it needs to be balanced (ph, ammonia, etc...) there are natural ways to accomplish all these things. Most of the chemicals you dump into the tank (other than declorinater) can harm the natural cycle of the tank. Just take your time before putting expensive fish in. Talk to your local aquarium store about the specifics of your tank. Find a good one that specializes in fish, not a general pet store.

Answer 4

when you say chemicals what do you mean? Carbon is a chemical as is salt. i dont use algae destroyers but if you dont have an RO/DI tap filter than you should add a dechlorinator. Be more specific as to what chemicals you are refering to.

Answer 5

if you mean elements (calcium, strontium, melybnium, etc.) unless you have a butt load of coral in a medium/large tank(55+) i would say no.
fish don't need it but sessile inverts and a few mobiles do.