water requirements

[gotticgs]

so what water can I use and what exactly needs to be done besides adding salt

I use to have a sw tank but it was years ago and all I used was tap water,salt and declorinator

and I do not remember having issues

so what would be proper for corals and frags ?

[cichlid1409]

RO/DI water and salt mix thats really all, the mix buffers and adds all elements needed.

[gotticgs]

what happens if i use non RO/DI

[cichlid1409]

bad problems with algae and most likely coral growth. keeping hard corals (sps/lps) would probably not work

[myjohnson]

what happens if i use non RO/DI

You want to use RO water. It's hard to keep the water stable as is. There is all kinds of junk in tap water that will cause algae growth.

A used RO unit on Marsh goes for 75 bucks.

I got a tiny tank so I buy SW and RO water from CP. It's 75 cents and 50 cents respectively.

My two 5 gallon bucks last me a month an a half.

[myjohnson]

so what would be proper for corals and frags ?

I got free corals for you foo!

Hurry up and get it going!

[i_am_poor]

You can use water from the windmill or kroger.

[Mattik]

If you do not have an RO system, buy distilled water at the store. Over time the RO is probably cheaper/more convenient, but especially in smaller systems, a gallon here or there of distilled water isn't too bad.

[nacra99]

In houston, I can use tapwater + prime for the intital setup. Then RO / DI for topups & partial waterchanges.
Running a fuge @ 24 hr light with fast growing macroalgae (like chaeto) while waiting for live rock to cure & the tank to cycle should help prevent the hair algae in the main tank by out competing it for nutrients.
If you are doing a FOWLR without a fuge or macroalgae, then i would not use tapwater but go with RO / DI.
Never use tapwater for topup otherwise TDS will skyrocket over time.

For corals, depending on type and how many corals you have and how often you do waterchanges, may need to suppliment with calcium, strontium & trace elements (like coralvite). I have a lot of SPS & clams, so i use a calcium reactor to ensure that there is a good amount of calcium available.
I add iodine to my tank because i have a good collection of inverts the skimmer pulls a lot of it out. Also, iron for good macroalgae growth.