diatoms dieing and replaced by green powder

[Buckchups]

I have been cycling my new tank for about 7 weeks. I got a great deal of diatom about 2 weeks ago and now it has started to die. In its place I have now gotten a green powdery substance on my glass. I had my ammonia tested at a LFS (he used a test strip) and it read 0 when I test with my Red Sea my ammonia reading is always around .01 and my nitrites are aroung .05. My ph is around 1.025.
I added a yellow tail damsel about 3 weeks ago and he is doing fine.

What is the green powdery substance on my glass?
Has my tank finished cycling?

[NU-2reef]

Are you sure your tank ph is 1.025. you do mean specific gravity= salt level
ph should be 8.1-8.4

I wouldnt completely depend on the LFS for water test.They dont make money by simply testing water but by telling you your water is fine and then selling you livestock, so be careful. i highly suggest you buy a complete saltwater test kit to self moniter your tank.

And ensure your filtration system is sufficient enough for you tank. Also are you using RO water for top off?very important.

you will always have some algae in the tank. to help control you can make sure that the tank is not recieving extended hrs of light/ filter is working efficiently/ and when you're convinced the tank has cycled you may want to add a clean up crew.

im sure the rest of the folks on 3reef are much more experienced than i am and can help you out even further.

good luck and best wishes with the new tank.

[NU-2reef]

by the way are you using the damsel to help with cycle or do you plan on keeping him as a permanent part of your inhabitants? If you dont plan on keeping him he will be a pian to get out. the clever people on 3reef have some intering methods of removal but they will agree that its a frustrating task.

[Buckchups]

THANKS for the advice. You are correct about the damsel.

[clownfish]

Hey dude, your tank will be cycled when you test 0 for ammonia, nitrate, etc..I was once adviced to use Seachem's Stability to aid in the cycling process and it did in fact help. Your damsel, depending on its size, won't be a problem, I kept mine and he's doin' fine, when I add a new fish, he tries to act tough and what not, but gets over it

As for your LFS using a "test strip" not sure how much you can trust that guy...mine LFS guys use Salifert and test my water free of charge and won't sell me a fish if my water parameters are off. Trust your gut, if your red sea test is reading a 0.1, go with it. I have the same test kit. Once your tank has cycled, take it slowly, add a fish and some cleaning crew...go slow, do not populate your tank too fast.