IMO you are doing too much to your tank all at once. There are too many things that can cause a tank to cycle, move, changing substrate, dead fish etc.... Cutting back on the feeding was a good start and doing the water changes is another. Have you tried testing your top off water and your WC water before adding it to the tank? Do you have an RO/DO unit or are you using straight tap water? How long was the tank set up before it was moved? Tanks left uncared for usually have high salinity due to evaporation not low as you mentioned so I am guessing someone was topping off without testing or doing water changes without testing salinity. Are you testing all levels around the same times of the day? The PH in a tank changes with the light cycle. Keeping smaller tanks stable can be a challenge due to any small change in chemistry can have a major impact to the tank. Whereas a large tank any small change is just that due to the large volume of water. Also you mentioned the decor in the tank so I have to ask do you have fake corals or decor in the tank? And finally the algae bloom is a natural part of the cycling process. Continue with the water changes (best weekly or every three days at most) to bring your levels in line and I wouldn't do more than 25% at this point. Just my 2 cents.