Will Nitrates affect a GH test?

NJ Devils Fan

#1 Devils fan
Oct 28, 2002
2,522
3
38
39
Yonkers, NY
members.tripod.com
I took a GH test in my big tank and it was like over 250+ ppm. Is this because the nitrates are around 40ppm? The test is fine because the little tank was around 100ppm.
 
I don't think that nitrates will affect those readings. What decorations/substrates do you have in the tank?
 
GH is testing (IIRC) for Mg and Ca ions in the water, so shouldn't be affected by NO3...

What do you have in the "big tank" It sounds like you've got some kind of limestone or aragonite rock, gravel, etc that is hardening the water.
Do you use any additives in the tank?
Do you ever just 'top-off' the tank without doing a water change? Dissolved minerals don't evaporate with the water, so will build up over time if you do.

OR, is there peat or something in the other tank that is bringing its hardnedd DOWN?
What is the GH of the tap?
 
AquariaCentral.com