I've tested all my water parameters and everything is perfect:
Ammonia "“ 0
Nitrites "“ 0
Nitrates "“ 0
Salinity "“ 1.024
Temp "“ 77.8°
pH "“ 8.3
FWIW, yellow tangs and purple tangs usually don't do well together. The yellow had already established territory when you added the purple. The yellow most likely harassed the purple, which caused stress which led to ich. Tangs are ich magnets.
Slow your roll a bit and spend some time reading. You added 5 fish to an uncycled tank (mistake 1), then added a purple tang (mistake 2), then had a several month period (perfectly fine), then added another handful of fish to a now uncycled tank (mistake 3), including a fish that would outgrow the tank (mistake 4) and you're now using display water as QT water (mistake 5).
1. You added too many fish, tank wasn't cycled. Ensure tank is cycled prior to adding fish.
2. Your tank is big enough for one (1) tang. No more.
3. During this fallow period, unless ammonia was being added in some way, nitrifying bacteria died off, so you had a biologically new tank. See #1.
4. EVERYONE plans on upgrading tanks before their fish gets too big. It rarely happens. Purchase for what you have, not what you want.
5. The point of QT is to isolate the inhabitants while monitoring/treating to ensure nothing gets transferred. If you suspect the tank water is causing problems, why are you adding it to the QT? Mix FRESH saltwater (with RO/DI) for your QT. They are separate systems, treat them as such.
I will let others expound upon everything that has gone wrong, here...
But, there is one BIG TAKEAWAY that you are hopefully getting from this experience: YOUR LFS's WATER SYSTEM HAS ICH!!!
I left the tank fallow for almost 6 months between my tank crash and now. absolutely nothing was in the tank, and i used some damsels for a test to make sure nothing was still in there for 6 weeks. Nothing came up so i bought some new fish...24 hours i brought the fish home they both had ich, i put them in QT and treated with stress coat and treated word for word using Kordon rid ich plus, changed the water like i was supposed to las tnight and naso was dead.
The thing is i don't think its the water...as far as i can tell it cant be the water. nothing is wrong with it. I'm wondering if its something else
This.
Purchase 1 fish at a time, quarantine for several weeks prior to adding to tank.
IF tank has been empty, do not add fish. Your tank needs to cycle again. Use frozen shrimp, not live fish, to do this. This process tanks 4-8 weeks minimum. During this time, do not add fish as it will lead to stress, which can uncover underlying ich problems.
how are you measuring your sg?
The thing is i don't think its the water...as far as i can tell it cant be the water. nothing is wrong with it. I'm wondering if its something else
this.
IT IS THE WATER or In the water!!!
You are still stuck with water chemical quality only.
It is the waterborne pathogens in the water in a closed system.
Water chemistry is only one facet (the easy facet) of keeping fish well. There is a whole dimension about the pathogens that is concentrated in the water due to the closed nature of an aquarium.
You have to really allow this idea to sink in. Really think about it.
So from what i'm gathering there still might be "some" ich left over from my past problem that took my tank out? I left my tank fallow for almost 6 months with a temp of 92°...i thought that would for sure kill everything. Plus i change 25% of water weekly
No, the tank hasn't been empty of water since i bought it, and i change 10% weekly like clockwork.
Do i need to do a 100% water change?
No, the tank hasn't been empty of water since i bought it, and i change 10% weekly like clockwork.