Conditioning water question

[Hollthulhu]

So, yes I'm new to this and full of questions! When we were getting supplies from the store, it was recommended we get Stress Coat (we got the one by API) to condition the water. The lady, who told me she'd had numerous bettas and her current one she'd had almost 2 years, said all we had to do was put it in our plain tap water, wait about 15 minutes and it was fine to put in the tank. The bottle itself has no instructions of a time to wait before using the water, so I wanted to ask people here what is proper, and if Stress Coat is all I need to be using.

I am not 100% about the facts of the tap-water here, but I do know it is quite hard due to limestone in the area.

I'm concerned about how we are doing our water changes because I'm afraid he has gotten what is referred to as "popeye".. which I'm still trying to figure how to properly treat, if I even can while a tank is still being cycled.

[LittleFish2012]

Personally, I don't use stress coat as a water conditioner. I believe stress coat is meant to restore the slime coat that may be lost during a tank change or when a fish is stressed. I don't use it at all.
I use an actual liquid water conditioner because where I am, we have hard water. Unless you have some other water softener, I recommend using actual conditioner. The woman you were talking to likely already had some kind of softener in her tap water system. I'm speaking from experience, of course, because I've had several bettas die from hard water.

As for your fish with popeye... it usually occurs from dirty water. And honestly, I don't know how to treat him if he's in a planted/cycled tank. What I would do is put him in a smaller hospital tank and give him a broad-spectrum antibiotic. But NEVER use bettafix or melafix- they contain tea tree oil that coats the fish's labyrinth organ, which could suffocate them.
Even if you're not certain whether your fish has popeye or not, you can add in a methylene blue solution. It's safe to use in unison with antibiotics, should you choose to treat him. Don't worry, popeye is rarely deadly. The worst that could happen (but likely won't happen unless it gets to the advanced stages) is that he could lose an eye. Clean water and meds should clear your boy right up. :)

[Kuro]

i use Seachem's Prime its one of the best water conditioners out there and very concentrated one capful of it is enoughs for a 50g tank so with little tanks most recommend just a couple drops per gallon so with only and even the 100ml bottle will last awhile if you only have one or two small tanks.

[efg321]

I use Prime as well and a little goes a long way! Great Product

[Hollthulhu]

How long do I need to let the water sit, though?

[babystarz]

With Prime, the water doesn't need to sit. Prime removes the chlorine and chloramines in tap water instantly.

[inveritas]

Prime is great (and doesn't seem to expire), just make sure you stir it in well before putting it in the tank!