In Desperate Need of Help for Saltwater Aquarium, Kelowna

[LeanneP]

Hi there,
I have been having some issues with an 86 gallon saltwater tank that I purchased 2 months ago that was all ready up and running. The people had it for 5 years and it looked very well taken care of when I got it. Everything was good for the first 5 weeks and then everything started going wrong. I have 2 clowns, 1 sailfin tang, a cardinal, 3 damsels and one giant damsel. I also had corals as well which included an anenome. It began to not do well and I realized it was giving off ammonia. It died and I also lost the rest of my corals. Now my tank had been a mess from the ammonia and I am having other issues as well. I have been so stressed from this tank and noone in Kelowna seems to have any more knowledge than me.
Levels in my tank:
Salinity: 1.022-1.024
Ph is too low: 7.7-7.9
KH-14 drops which is way to high again. I added OH balance to try and get the ph up and it says it doesn't affect KH and calcium but now I am not so sure.
calcium in 500
Phos: 0
Ammonia was up to 2ppm but I am not sure now as the test goes blue, guess because I have added Prime to break down the ammonia.
Nitrite and nitrate are at 0 which makes no sense to me.

I am desperate to get my tank back to normal. I have done 2 x 20 gallon water changes in the last week and plan to do one on Friday again. I was adding Ammo lock every 2nd day but I have since changed to Prime. The fish have started to do better now. I am very confused about the readings that I am getting from my levels. My ammonia reading is blue which is not even on the card. And how can my nitrate and nitrite be 0? I just had to buy a new filter as mine started leaking everywhere. It is a Rena XP3 canister filter and I also have a hang on the side protein skimmer. How often should I be replacing carbon, sponges or filter media with the ammomia present?

What is the best way to get this tank balanced again and how can I get my ph up and stable or is it better to wait until all the ammonia is completly gone since higher ph is not as good with ammomia? It was on the lower end before this all happened and now I am begining to wonder if that is why the anenome died. Any advice would be greatly appreciated.

Leanne P, Kelowna