issues with cycling new live rock

[PurebloodFerret]

Hey everyone. I have a question about cycling live rock. We have a new 150L tank which we are slowly trying to build, and so far have an anemone, 2 clowns and a couple of corals, and a second 30L tank we use as quarantine and acclimation tank. We've put two pieces of live rock in the quarantine tank (one after the other) to cycle but keep running into massive issues where the water just goes putrid no matter what. It gets to the point were sure everything has died on it, and even ended up changing the water out because it was just out of control and the room smells like death. We can't figure out why this is happening we check the levels regularly and keep the pH at 8.3 and sg at 1.026, and it's fitted with a filter, protein skimmer and air stone. The protein skimmer was acting up the other day, filling the reservoir way too quickly (every hour or so) and I took it apart to clean it. I read that it could be due to the air inlet being clogged but nothing seemed blocked anywhere.
My DH and I are just getting frustrated with buy perfectly fine, premium live rock from lfs and when getting it back home it just tantrums in our quarantine tank. Especially when im think that the rock might already come cured, because the lfs guy was surprised when I said I put it in a separate tank first to make sure it's fine and let it cycle.

Any suggestions would be appreciated!

 

[aquandrew]

are you adding an ammonia source to the qt?

 

[ColBen112]

Have you ever used copper in the qt? If so that's why the live rock algae is dying.

 

[PurebloodFerret]

No I'm not adding anything to the water except small amounts of pH buffer when that goes out. We've never put anything in the qt tank like copper. Only when it was our main tank we'd put iodide supplements and the standard ammonia neutralisers etc

 

[mr_X]

There must be a lot of die off on the rock then. I would not put rock in the QT tank. If you have to use copper or some other medication in that tank the rock will hold it and it will never be any good again.
usually people just toss a couple lengths of pvc pipe in the bottom of a QT tank for the fish to hide in.
You should never have to use ammonia neutralizers. If you have detectable ammonia in your display, you either are overfeeding, put too many fish in at once, or haven't cycled the tank properly.
The same goes for iodide really- there's plenty of that in your salt mix and without testing for it, blindly adding it can cause negative results.