Originally Posted by Rolo737
By hardness you mean KH? I'll just assume so and that means you have about 16 ppms CO2. Kind of on the lower side.
Can we have a pH and KH reading of the water you use to change. If that has lots of CO2 - that should the reason.
I'm surprised though that you have any pearling at all with 0 nitrates. How are your phospates and potassium.
Ok, I'll try to answer your questions as best I can:
My test kit (Aquarium pharmaceuticals) simply calls the test "Water Hardness" and reports it in PPM. It also gives a conversion to show it in German DH and I'll report both for you below.
Here are the numbers you needed:
Tank Water tested 2 days ago (6 days since last water change)
PH= 7.2, Water Hardness 150 (8.4 DH)
Water from my tap (after dechlorination) (today):
PH= 7.4, Water Hardness 160 (8.96 DH)
Tank Water tested one hour after 20% water change today:
PH = 7.4, Water Hardness 160 (8.96 DH)
This is strange since by my calculation, these numbers mean that my CO2 content went from 16.7 ppm before the water change to 11.27 after the water change. An yet .... all the plants started to pearl after the water change. What am I missing ?
The only other thing I can think of that might be relevent is that I have about 1.5 inches of peat in my filter canister to help soften the water.
Oh ... regarding your point about Nitrates, my test kit colour indicator shows 0 ppm and the next step is 5 ppm. The best I can tell you is that my Nitrate level is betwen 0 and 5 and by my eye, very close to zero.