Live rock turning brown

[pensky]

I started my tank about 3 months ago and after 4 weeks from the begging I add some livestock and live rock. On the second month I added a bit more live rock (5# first time and 10# second time). Now on the 3rd month the rock I put in a month ago was white and now is turning brown. Is this a good thing or a Bad??
The first pic is at the time I put the 2 batch of rock 1 month ago
The second pic is of the rock right now
The thrid pic is a close up right now.
What do you think GOOD OR BAD??

 

[who dey]

so what did you have in your tank to start the cycle

 

[pensky]

I use four fresh water molly and slowly turning them to saltwater and left them in for a month (29 gal)

 

[pensky]

I had CC on the bottom and only 5# LR. about a month and 1/2 ago I swithed the CC to LS 40#. but I never had any problems with that and they only test that is not zero is nitrate witch is 20.

 

[who dey]

it's possible when you added the new LR you have created a mini cycle. what are your parameter readings. The combination of the mini cycle and possibly tap water (i hope not :thinking would create diatom growth

 

[pensky]

I used tap water to start and used R/O for water changes ever since. My ph is 8.0 used treatment of ph up but i have used this before also. My ammonia is 0, Nitrite 0, Nitrate 20. Sal 1.022 Temp 82 Those are the only test I have.

 

[who dey]

you should probably test your tank for phosphates which could be fueling your problem since you did start your tank w/tap

 

[pensky]

the only clean up crew i have is 5 bumble bee snails should i buy some turbo snails immediately and if so should I get 10 astrea snails or 2 mexican turbo

 

[who dey]

i have found that turbo's do wonders. i only have 2 turbo's and man do they clean house. i keep my crew small so there is more for my linkia to feed on. everyone will have their opinions on clean up crews but the more you have cleaning the smaller your headaches will be.

 

[pensky]

Once I purchase some turbo snails to fix the diatom problem would it be ok to add another 5 to 10 # LR eventhough I have not fixed this problem yet?