A little concerned

Hey guys, so I recently moved my tank. There was a small leak in my skimmer so I had to take it all down to clean up the mess that was on the floor. In doing so I decided to rearrange my live rock, and I added a bottom to the tank, I hate BB. I probably lost about 30% of the water maybe 40% when moving it. I only had two Clownfish and they seem to be doing fine.



Anyway, everything seemed ok, on my last test but today, after buying 6 red tip hermit crabs. I tested my water and I feel that I now have some cause for concern.



25gal tank

26lbs live rock

5lbs sand



pH - 8.0

Ammonia - 0.25

Nitrite - 0

Nitrate - 10-15



Is there anything I can do to bring down these levels. Just checked my tank has been cycling for exactly 6 months today, and the move was maybe 3 weeks ago...



Thanks guys!