Heavy Bio load with zero Nitrates. Normal?

[Chefken]

I have two tanks: ten gallon and 52 gallon both with very heavy bio loads. The 52gallon has over 48" of fish in it including a 10' IT, 6" BP, 6" Frontosa, some fairly large cats......you get the idea.

The tank has been set up for over two years and is filtered by one xp3 and a bio350.....Sand is the subtrate. No live plants. I do absolute textbook maintanance.....two 20% water changes per week with a 50% change every other week. i feed heavy once per day in the early AM.

My water parameters are zero across the board. No Ammonia, no Nitrite, and most suprisingly zero Nitrate. Ph is 7.5, temp 80 degreesF. These readings have been steady for two weeks. I have steady algae growth on the glass....not crazy. i do read somewhat high for phosphates.....they are in my well water. What do you all think? The ten gallon which is heavily planted has the exact same perameters but is underfiltered.

Thanks in advance! Ken

 

[12 Volt Man]

check your test kit.

shouldn't have that in an established with that sort of stocking and water change schedule unless its a heavily planted tank which it isn't. (assuming proper feeding of course)

if you are underfeeding a bit, the nitrates could be lower than you would normally expect.

 

[slimmer]

Make sure you really shake the second bottle when checking for nitrates.

 

[Chefken]

That was it. I am now reading 25 parts of nitrate. exactly where i thought i should be in between water changes. Funny how my last nitrate kit had three chem components and one had to be shaken for 30 sec. This one....API is a little vague on exactly what to shake. THANKS!