View Full Version : Question: Raising gH and kH

25th October 2009, 23:17
How do I raise the gH and kH of the water, I jsut done a water change and added carbonate hardness powder and tested it again and both readings are sitting on mid-low. The pH is sitting on about 7.6

26th October 2009, 00:39
Have you tried freshwater aquarium salts?

26th October 2009, 04:15
I think that as long as your pH stays steady, mid-low hardness is fine.

Isn't aquarium salt mostly sodium chloride? I don't think it will do much for hardness.

I keep a small piece of limestone in some of my tanks to prevent the pH from dropping.

26th October 2009, 09:52
Freshwater conditioning salts for aquariums do mainly contain sodium chloride but other salts such as calcium sulphate, potassium chloride, sodium bicarbonate etc. are also present. With most commerical products formulated for freshwater aquarium use, one level teaspoon (5g) will increase hardness by approximately 120ppm per 10L of water.

26th October 2009, 14:30
Tht's interesting! For how long?


26th October 2009, 21:57
Until the total water capacity changes such as water change, evaporation etc. Some salts will be used up by plants and even the axie but they are negligible in comparison.

27th October 2009, 02:33
Ok thanx for the replies, I am currently using 1tb salt per 15 litres of water when I do water changes. But wondering whether that is a little too much?

1st December 2009, 15:52
Bump :happy:

1st December 2009, 16:16
Sorry you haven't had a reply before now.

Personally I don't use any salt in water changes, perhaps now you have bumped your post up you'll get someone with more experience reply.

1st December 2009, 19:08
Hopefully. I have never worried about either gH or kH in the past but I was told by adding a small amount of salt it would help combat disease.

2nd December 2009, 00:25
I live in an area where the water is "liquid rock". However in the past I lived in soft water areas and had success with the aquarium salt method for short term. It works exactly as Darkmaverick describes.

For long term I kept a sack of limestone gravel in a large plastic garbage can which acted as a reservoir for water changes. It did double duty as it was also inoculated with Daphnia magna. This method is only suitable if you have the space though.

I have read of folks using a similar method by just hanging a mesh bag with some limestone in it in the corner of the tank.

Either way, if you intend to adjust hardness, I highly suggest you invest in a good quality liquid reagent based test kit for hardness and pH.

You may also want to practice the adjustments in a non-inhabited container until you get the hang of it. Sometimes such chemistry adjustments can be tricky and can cause health issues in your pets due to extreme variations over a short period of time..

2nd December 2009, 00:57
Hi Jess,

Firstly you should not add aquarium salt directly to the main tank water. The best way is to gradually increase the hardness. You can do this by only adding 1 level teaspoon/ 10L water to the fresh water bucket when you perform water changes (the water you top up the tank to replace the old water removed). Over a period of time, the hardness will gradually increase but still within a safe limit.

You can place a piece of limestone or crushed shells in a stocking bag and suspend it at the corner of the tank. It can also raise hardness and prevent pH from falling by providing a buffer effect.

Regardless, you will need to get a water chemistry kit that tests for hardness as well to be able to monitor the levels safely.