So frustrated!! Help!!

[ChiTownRomeo]

I swear I am at my wits end! Tank has been setup for 7 years. for the last 2 years mostly all the corals look like crap. Lps won't open fully, Sps bleaching or browning out. BUT EVERY TIME I do a 20% water change once a week they are open fully and fat and happy. Very next day they look like crap again!! Especially my torch, hammers and frogspawn. I swear I do not understand it. Everytime I do a water change, everything is beautiful! But when I wake the next day....back to normal. I haven't added anything, Use the same salt, tds is 0 in makeup water. Getting real frustrated.

 

[Autumnsky]

What about are you using for water, RO/DI, do you need a new filter membrane, old membrane can cause problems. Which salt are you using? Maybe someone will have a good answer.

Do you think that maybe you could use a new layer of fresh sand. I am no expert here with SW. Could it be Nitrates in the sand removed with the pwc, then return the next day, just enough to bring the corals down? Then be processed by the LR. Just thinking out loud. You suck up a small portion of sand at a time and then replace until it would be more or less new.

What equipment / setup are you using on the tank?

 

[ChiTownRomeo]

What about are you using for water, RO/DI, do you need a new filter membrane, old membrane can cause problems. Which salt are you using? Maybe someone will have a good answer.

Do you think that maybe you could use a new layer of fresh sand. I am no expert here with SW. Could it be Nitrates in the sand removed with the pwc, then return the next day, just enough to bring the corals down? Then be processed by the LR. Just thinking out loud. You suck up a small portion of sand at a time and then replace until it would be more or less new.

What equipment / setup are you using on the tank?

Its a 55 gallon with alot of corals but only a pair of clowns so not a big bio load. I have a skimmer rated for 100 gallons that skims like crazy. I'm wondering do I have enough bacteria in the tank. Yea it's a old tank but I have real reef rock brand and it isn't as porus as other rock. It's 45 pounds of it in there but honestly that might be the problem....