Kh And Gh

[zelda_leonhart]

Hello all,

Just wondering if it is completely necessary to monitor kh and gh in fw aquariums.

I've had my tank set up for quite some time now and never monitored it previously. I do however check the other stats at least twice a week (maybe I'm paranoid!!!). Provided everything else including pH is being monitored is it completely necessary?

I bought a API gH and kH kit the other day out of curiosity and got readings something like: kH = 0 and gH=200 (no idea what the units are and I'm at work so can't look!) So I believe this means that my water has no buffering ability to keep pH steady but I monitor that anyway?

What are people opinions about this?

 

[Craster]

It's worth doing it whilst cycling, because that way you can avoid a pH crash which can stall your cycle. It's also worth doing if you have a planted tank with plants that have specific hardness requirements. Otherwise, there's probably not a great deal of value in measuring them.

 

[OldMan47]

Hi there Zelda. I must agree that you are overcautious with your testing. Once I have a tank well established and have the maintenance needs for that tank figured out, I test it if I ever see a problem with the fish. Otherwise, I maintain a proper water change and cleaning routine and don't worry about it. I do understand the chemistry but usually ignore it. I make an exception for my cory breeding tank because they require quite soft water compared to my tap water. That means that without testing, the mix from my tap and from pure water that I mix into it will not come out right. That testing for me is a test of TDS using an electronic meter. KH and GH can be useful information if you are having a hard time getting good pH buffering effect from water changes or are facing similar problems. In your case it looks like you may have a buffering potential problem. If you have stable pH, you have enough buffering for your maintenance practices and your fish load. If you find you need more pH buffer, there are chemicals that can be added to give the pH some stability. Otherwise those tests are really not needed. If I didn't have the TDS meter, I would be using my GH kit to guide how much pure water to mix with tap water but the TDS meter is easier to use for my purposes. For me, with a KH around 12 degrees, I almost never look at it. No matter what I do, it is almost impossible for me to move my pH.

 

[rdd1952]

API test kits measure in degrees German and ppm. So if the color changes on the 5th drop, then your water is 5 degrees German. Of course, that can be converted to PPM which is what your 200 is. Your water I odd in that generally, if KH is low, so is GH and the other way around. So having 0 buffering capacity (KH) and hard water is very odd but not unheard of.

As mentioned, they aren't terribly important to monitor. Unless your water supplier makes a major change, it isn't going to change on it's own.