Is my water params possible?

[pulp2000]

Hi all

I took the water params of my 3 ft tank.
Its as follows:

pH: 7.4
KH: 2 dKH
Ammonia: 0
Nitrite: 0


My KH seems to be a bit low to properly buffer the tank pH but why is the pH at 7.4? Shouldn't it be less than 7 given the low KH reading? I got a packet of coral chips in the cannister filter for pH buffering. Look forward to some replies! Thanks in advance!

[juggler]

Coral chips is alkaline and therefore your pH is alkaline.
If you inject more CO2 to bring down the pH, you will also discover your kH can rise.

[bclee]

Just to put things in perspective... pure water with zero KH has pH of 7.

Any KH in pure water will push pH > 7. Of course when water is exposed to atmosphere, dissolved CO2 will slighly lower the pH of the water. Dissolved organics or other buffers will also alter the pH value.

Actually, pure water with KH 2 and CO2 level at ambient level, the pH should be near 8.

BC