How important is a GH/KH test kit?

[JCinPA]

I am learning about water testing, and have used the API Master Test Kit, but that does not include a GH/KH test. That test is cheap at Amazon, but question is how important is it for me to have?

My local water reports indicate GH of 150-160 in my area, but they don't list KH.

A) I don't know if it is important
B) I wouldn't know what to do with it if I had the information

Am I OK with the Standard API Master Kit, or should I get the extra test kit?

Thanks!

 

[bgarthe]

Yes get the GH and KH test kits. One really does need to know both. And if after testing, one is not sure about what or how to do things to remedy, just post and members will gladly assist. Don’t forget…..we had to learn all that too. Seriously…..both of those are very important and, imho, crucial in maintaining a healthy tank. KH has a direct relationship with pH and GH is essential for fish mineral intake/osmotic status.

To give you an example, I have found that my higher pH of 7.8 or so can work with fish preferring a lower pH if the GH and KH is kept lower. Had I not tested my GH and KH, I may never have been able to successfully keep many of my tetras and certainly not the Discus through the years. I personally feel that GH is too often overlooked by many keeping fish and many of the issues that arise stem from GH factors.

 

[JCinPA]

Well, that’s a great answer! Just ordered it. I wonder why they don’t put it in the API Master Kit. Oh well, will have it soon.

Thanks much.

 

[anewbie]

Generally speaking gh and kh are stable in most regions - if you can get your pet shop to test them then they can give you a good idea what fishes will work well in your water.

In general ph is a worthless number for many reasons but knowing gh and kh can be pretty important.

 

[JCinPA]

The local pet store uses strips, and I trust the API liquid tests more.

Makes sense it is pretty stable. I ordered the smaller size kit for that reason.

 

[JCinPA]

Well, this was very informative. I'm now kinda glad I have a 10 gallon "learn stuff and recover from screwups" tank. I'm going to use this to learn on before getting a 55-75 tank later.

I don't have any plants yet and only a guppy, so I'm not too worried about this. But I will add plants soon, and play with this test kit when it arrives. Thanks so much for the info!

 

[bgarthe]

You’re digging in, willing to learn, trying so hard, and that is SO cool. Your fish will thank you for years to come. Heck….I’ve been in this for many decades and I’m still learning.

 

[Naughts]

1) You only need these testers if you are adjusting your water for specific GH/KH/pH. This can be difficult and complex.
2) Don’t adjust your parameters for your fish. Instead, buy fish that are suited to your water (for JCinPa a GH of 150-160).

 

[Essjay]

My local water reports indicate GH of 150-160 in my area, but they don't list KH.

Does the report list "alkalinity"? That's what water providers call KH. My younger son once worked for a water testing company and he told me the word 'alkalinity' comes from the method they use to test KH.

 

[GaryE]

I have the advantage of decades of fish keeping and breeding experience, and make use of the local water reports. They're very informative around here, with local reports by pumping station. I can see a monthly report taken from a site I can see from my back window.

GH and KH (and what @Essjay said about alkalinity holds here in North America too) are essential info before you buy fish, if you're concerned about longterm success and ethics. Fish have to keep water out of their bodies, and evolution has tuned their large kidneys to do so. How they work depends on the water they evolved in - soft water fish have different filtering abilities compared to hard water ones. Keep a fish in the wrong water chemistry and the kidneys are going to have to work in overdrive to maintain an osmotic balance with their outside world. It can take years off their lives.

If you decide to someday breed fish, eggs also filter minerals out or pull them in, depending on the natural history of the species.

Put many livebearers from hard, limestone/dead coral based freshwater into Amazon water and they'll quickly die from an awful, painful looking neurological condition.

So if we are at all serious about fishkeeping, we need to know our water. It's not going to change a lot from water reports. We don't all have access to those services. But the readings provide essential info for choosing fish. One of the sure signs of a wishful (non) thinker in this hobby is someone who says fish can adapt to all tap water. It isn't so, as convenient as that sounds for fish sellers. It's become a comforting myth in the hobby.

The hardness kits give information that's useful, and you can never have too much useful info. I measure my water regularly with an electronic device, to make sure my breeding tanks aren't picking up minerals from rocks, etc. It matters a lot for the fish I enjoy keeping. I haven't used an API master kit for 30 or so years, as the cycle here is managed by maintenance - I'm not starting and stabilizing it as a newcomer is. I don't need the nitrogen cycle readings as I have clean tapwater and a routine. I want to know the hardness at all times though.