dosing nitrogen with nitrates present?

[Linda S]

I have a 20, and a 29 heavily planted. I am dosing the seachem line of products. My thought is if I am shopwing nitrates in the tank I do not need to dose with the nitrogen. Am I on track with this or should I be dosing it anyway? The nitrates are about 10ppm after water change.

 

[plantbrain]

Depends, this assumes the NO3 test kit you mention is correct and accurate at 10ppm.

What was the NO3 prior to the water change?
What is the tap water's NO3? Ask them and see.

If you do a few large water changes, in a row, then the NO3 should be very very low if the tap is good.

What you want is not too much, and not too little, 10-30ppm is a good range, but this assumes good test kits and methods, so you will need a reference to compare the reading to, so standard solutions that are known are used to verify a method/test kit etc.

Color matching is also dependent and not always very clear with test kits.

Be careful unless you plan on calibrating them correctly, it's more "a guess" at that point until you do. Same for PO4. Most pH/GH test kits tend to be okay. Do not even bother with Fe.

Regards,
Tom Barr

 

[KarlTh]

Certainly on the API kits the colours are so damned similar on the higher values that you need eyes like a colorimeter even if the test is accurate.

 

[Linda S]

thank you Mr Barr and KarlTh, I use the API test kits, don't measure for PO4, and because I have flourite or root tabs I don't test, or dose with fe