Difference between KH and GH

[Rush07]

What is the difference between KH and GH? My test kit test GH, but I see KH discussed more often. The GH in my 55 gallon tank has shot up from 6 to 17 and the pH has dropped from 7.1 to 6.4. I know peat will soften the water but it will also lower the pH more. I have heard that doing a water change with distilled water will bring down the GH, but I would rather solve the problem if possible rather than use a temporary fix. Amonia, nitrates and nitrites are all zero. I have 2 Dempsys, a cichlid pike and a royal pleco. I am running a Whisper 60 and a Fluval 305. No live plants.

Are these numbers dangerous? The fish seem OK, but I have never had water that hard.

 

[Lotus]

This article should help you: http://www.drhelm.com/aquarium/chemistry.html

Can you tell us what decorations you have in your tank? There is definitely something causing problems. Also, are you using any pH adjusting chemicals?

 

[Rush07]

Thanks for the link. I will check it out now.

Decorations: 4 plastic plants, a fake tree trunk and cave that are plastic I think (just regular decorations from PetCo), and 2 pieces of bogwood. These are fairly new as I have only had the pleco for about 2 months. I have heard that this can cause the pH to drop, but I am less concerned with that than I am with the hardness of the water.

I have not treated the tank yet because I feel like I am not sure what I am dealing with. I would feel more comfortable if I knew the root cause and then I could address it. I would like to avoid adding chemicals if there is a "natural" way to adjust it.

 

[Lotus]

What kind of substrate do you have? You might want to take a water sample to a LFS and have them test the GH, just in case your test kit has gone bad or is giving you a false reading.

 

[Rush07]

The substrate is blue gravel. Just regular fish store gravel. I think I am going to test it one more time and if I get the same results, I will take it to the LFS to have them test it. Thanks for the advice.

 

[Charlius]

The thing I'm wondering about is if you have no live plants, how can all ammonia, nitrite AND nitrate be at zero?? Tell us your secret!

 

[Rush07]

Lucky, I guess?!?! I run ammonia chips in the canister filter. I have to or it shoots up. I have never had any issues with nitrates, and I don't have a nitrite test, but take it up to the LFS every so often and they keep telling me it is at zero.

I have had live plants in the past, but gave up with the Dempsys. I can't keep them in place.

I don't really know what I am doing but I guess I have been pretty lucky. Or maybe I have a really bad test kit! I really need to find out why the water is so hard. It has stayed between 4-6 for the 3 years I have had it running, but now it is at 17. I am going to re-test tomorrow. It may have been a false reading.

 

[Orion]

Ammonia should always be at zero and there shouldn't be a need for anything like ammonia chips (??ammonia removers I guess?). A cycled tank will have a reading of zero ammonia and nitrites. So if you have anything other than that then your tank isn't cycled.

 

[Intravenous]

maybe the ammonia chips have bound the ammonia? That would explain why there is no nitrates because if the ammonia has always been in the bound form then the cycling bacteria would never have developed since they can't use it ?

 

[Rush07]

Its sucks being stupid. I have been trying to figure out water chemistry for years and just when I think I get it I don't. I thought that I wanted ammonia, nitrates and nitrites at zero. Is this not so? I have been running the Ammonia chips in the canister filter for a while but I could take them out and see what happens. Would that be the right thing?

 

[Orion]

There is always something new to learn about. Your not stupid, at worst only ill-informed

Zero ammonia and nitrite is a good thing. It's the only thing to strive for with a tank, and the easiest. This indicates a cycled tank.

What I would do is to start removeing a little bit of the chips at a time. Don't take them all out at once. This will allow smaller amounts of ammonia to build up in the tank, but should keep things from getting toxic. Do this over the course of a month or two and keep up with water changes and keep a close eye on everything and it should be fine.

If you remove them all at once, then good chance is that it will throw the tank into a full cycle. This can be very deadly to your fish.

 

[Rush07]

Sound good. I will give that a try.

 

[bigredspecial]

I thought that I wanted ammonia, nitrates and nitrites at zero. Is this not so?

Although that would be ideal, it isn't realistically possiple. The end product of the nitrogen cycle is nitrate, so in order for ammonia and nitrite to be zero, there will be nitrates.

This is assuming you don't have anaerobic bacteria, which convert nitrate to nitrogen gas, but that's a whole 'nother topic.

 

[christianblu]

What is the difference between KH and GH? My test kit test GH, but I see KH discussed more often. The GH in my 55 gallon tank has shot up from 6 to 17 and the pH has dropped from 7.1 to 6.4. I know peat will soften the water but it will also lower the pH more. I have heard that doing a water change with distilled water will bring down the GH, but I would rather solve the problem if possible rather than use a temporary fix. Amonia, nitrates and nitrites are all zero. I have 2 Dempsys, a cichlid pike and a royal pleco. I am running a Whisper 60 and a Fluval 305. No live plants.

Are these numbers dangerous? The fish seem OK, but I have never had water that hard.

KH (carbonate hardness) reflects the ability of the water to maintain a stable pH, GH (general hardness) reflects the total mineral content of the water