Help. Help

[sea gnome]

Yesterday I noticed that one of the green chromis had some abrasions on the side before I did a water change. I have noticed it before and he is fine. After doing water change and tank cleanup I noticed that one of three clumps of xenia doesn't look as happpy as it does usually.

Today on getting up the abrasions on chromis look worse and even more awful is "Stripey" our six line wrass who is breathing fast,looks like he has ich and some funny glistening spots on head area. He doesn't want to eat and looks near death. What is wrong? I use only ro/di water from store ( it is shut for mechanical problem yesterday and today, maybe something bad in water?). My chemistry is fine has been stable for months. Yesterday the make uup water pump had stopped working, no oil slick or funny smell to it so I used it. Used windex to clean glass. Only used it 3x in past and always with canopy on except yesterday, but I didn't spray it on but poured it onto cloth first. The temp. in tank has been very stable throughout summer.

I am going to do a water change now with the 5g of water I have left, should I use tap water for rest or leave it be. I have a well and supposed good quality, used it for last tank with few problems. My on ro/di sylstem goes in next week. I think I need to do major water change.

Possible problems, poor water from store, pump contaiminated make up water (looks like impeller got sand in it and has scratched magnet part, ?magnet shavings in water.

The fish I have had for 2years, I don't know what I'll do if I lose all the livestock as I have just started tank from scratch in new year and have spent so much money already. I am so worried about my fish and the future health of the tank. Any suggestions welcome.

Rachel