just taken PO4 and NO3 readings...

[Tiggs]

Slowly upping my dosing....the PO4 is at 1 so thats fine now - just need to figure out how much is used to keep it there.

but NO3 is still reading 0...even allowing for an iffy test kit its still low (the water remains crystal clear in the tube- i added some nitatre from my dosing and it went pink so the kit does work!)

So far i have built up to adding 3ppm a day...been on that for a few days and was on 2ppm for 5 days before that - 1ppm 5 days before that.

Could i still be showing 0 ?

 

[iggy01]

That's the problem with nitrate test kits. You're never quite sure if they're working or not. You might be better getting a bucket filled with tap water and test it for nitrate. You can then add a known quantity of KNO3 from a stock solution, using Chucks Calculator. Test the water again and see what you come up with.

There again, it is always possible the nitrate is being consumed as quickly as you are adding it. High light tanks can use up to 4 mg/l nitrate a day.

Good luck!