I think it is odd also - summary of information.
Day 38 now of fishless cycle
25 Gallon Saltwater Tank
18 lbs live rock - 10 lbs base rock
2-1/2 inch + or - live sand bed
Added Bio-Spira on day 1
Started testing water on (on day 5) using test strips
Added a small piece of shrimp on day 12
I did not notice a spike in Ammonia or Nitrite (bought a API test kit around day 15)
Ammonia only reached 0.50ppm (tested daily)
Nitrite has not moved off 0ppm
Nitrate was at 40ppm then I did a pwc
(3 gallons on day 33) - ammonia and nitrite levels were 0ppm. Nitrate was at 40ppm for around 9 days. When I did the pwc
my nitrate level was at 5.0ppm 24 hrs after the pwc
and started climbing again.
I dosed Ammonia to 4PPM 36 hours ago to make sure cycle was complete.
Temp is 80.4
High Range PH 8.0
Strange that Ammonia is heading to 0 - Nitrite has not changed - Nitrate is going toward 40 ppm
I will take a water sample to my LFS
today and have them test ? ? Any other suggestions?