rock turning white

[serg11]

Hello. well its about 5 weeks since my 29g tank has being up and going. My live rock is turning white. This is the situation, I started with 30pounds of live rock used saltwater from lfs to fill up tank, had a couple of hitch hikers, hermit crab, snail and 2 seahares (pict) I believe they are. I test every other day the first week had ph8.4 ammonia .5, trites .25, trates 10, salinity 1.023, temp 78. I used NITROMAX Marine every other day for 2 weeks which creates an ammonia processing system. 2 weeks into it I noticed rock and tonga branch had a outbreak of brown algea. Found out it was diatom.I put my lights on for 6hrs from 8hrs all my levels at this point looked great ph8.4, ammonia 0, trites 0, trates 0. salinity 1.024. So i got some turbos for diatom. I did noticed one rock was turning white on about the 3rd week. I use ro water to top off. Know on the 4th week my trates were up to 10 then 20 and all other test were good so I did a 20% water change (5gal) and I also moved my tank to the other side of room away from window (there was no direct sunlight but to be on the safe side). At that point of doing the water change and moving the tank I also took all my rock out and just rinsed and scrubbed the tonga branch under tap water since it had the most build up of diatom the other rock I left alone. my power heads, filter, skimmer were all off for about hour and half during this process. Skimmer, power filter, inside tank got cleaned and sand got clean as well. I noticed filter bag was brown so ordered new ones still waiting for them to arrive. Got Everthing back on line and used saltwater from lfs to refill. Before I put water in I brought temp up to 78 and checked salinity to make sure they match and had it for 48hrs. 2 to 3 days after this all of my rock started to rapidly turn white. all my levels check out but my trates are up to 20 today ph 8.4, ammonia 0, trites 0, temp 78, salinity 1.023. could It be the seahare, is my rock dieing if so when will I see life again on rock. HELP..........
I ordered a calcium, carbonate hardness, phosphate test kit, I should get it anyday, so no numbers on these yet. do I need these test. Plan to have fish with live rock. like to have corals in the future.
whisper40
hang on back skimmer
2 power heads for flow
day light and actinic blue both on for 6hrs
temp 78

 

[hatessushi]

You will probably see life again on the rock but everything died since you took the rock out and scrubbed it with fresh tap water. I would not have done that. Everything seemed to be going fine until you did that. you will need to wait for it to cycle again.

 

[1journeyman]

Yup, basically scrubbing with tap water was a big "no, no". Your tank was cycling beautifully; diatoms are normal in a new tank. The "white" was probably coralline algae dying. Also normal.
Be patient, and monitor. Not sure how much damge was done, but you may need to add a bit of fish food to tank and let it cycle again.