Hi everyone. OK, my tap water is around 4 degrees KH (71.6 ppm) for both KH and GH. Ok, so I set up my new 55 gal and was going to start silent cycling tomorrow and just took KH and GH measurements and they are unbelievable high--like much bigger than any scale I can find. I have repeated the test until I'm almost out of reagent. This can't be right, correct? Something chemically is interfering with the test. I have CO2, organic eco-complete-type substrate (from aquarium plants.com--their brand), carbon filtration (for now)...what could explain this? This water is one day old! My plants come tomorrow and I'm scared to death.

The SMS type substrates occasionally cause KH and GH problems, I think. If you just change 50-75% of the water a couple of times in succession you might get back to good conditions easily. Adding plants right away is good, not bad. It is fish that need to go into a tank that isn't still cycling.

Oh man, thank you so much. I was totally freaking out. I will change 75% add the plants and monitor. Should I do daily changes until things even out?

It isn't a panic situation, so I would watch the KH and GH to see how fast they are rising, if at all, then change water again based on that. If you had fish in there the wild swings in GH and KH (Total Dissolved Solids) would be bad for the fish, but you don't.

Those who reported that their SMS caused something like this, also reported that the problem went away after a few water changes, as I recall. And, I think that substrate you have is really SMS.

Today I did an almost 100% water change. The GH reduced drastically to 10 degrees but the KH is still off the charts. Plants arrived today. Will be doing water changes until this hardness thing is under control. Attatched photo of first day with plants. So excited to start my first high-tech set up.

This is off the subject, but I think you will get much better results if you replant those bunches of Rotala (?) as individual plants spaced about an inch or less apart. That way they all get enough light to grow well. The tank is going to look very good as soon as it clears up a little more.

Doing more water changes doesn't harm anything, so if you really believe that the KH is off the charts, just do another big water change.

Thanks for the continued help. I am braking up the Rotala right now.