Water hardness confusion

[Seb2502]

Hi everyone,

I don’t know what’s going on in my tank regarding water hardness.

My test strips(tetra easy strips) are telling me that my tap water is very soft.

However my tank that I use the same water from is telling me that it’s very hard.
I’m not sure what is causing the hardness. I’m thinking it’s the water conditioner if that’s possible, or and more likely my substrate. I’m using a gravel substrate that I can’t remember what it said on the packaging but I’m thinking that it contains crushed coral maybe.

I want my water to be soft btw

If anyone can help please let me know


The first photo of the test strip on the left is my tap water.

Second photo is the 75g aquarium

Third photo with the test strip on the right was taken from the tank

 

[Byron]

Calcium (primarily) and magnesium are the minerals involved in GH, and calcium will dissolve from rock, gravel, or sand that is composed of calcareous mineral like limestone, marble, dolomite, aragonite, coral, shells, etc. The white bits of the substrate could be such a calcareous material. The chunks of rock might be involved as well.

Water conditioner is not going to impact GH/KH/pH.

If you want softy water, presumably you intend soft water fish species. The substrate will likely need to be changed, or the rocks removed. You could do a test on these to see which is the culprit. In a clean bucket of tap water, place one or two of the rocks. In another clean bucket of tap water, put a couple cups of the substrate but rinse it thoroughly under the tap before putting it in as you do not want it contaminated (so to speak) by the tank water. After a day, or two, or three, check the GH in the two buckets.

 

[Seb2502]

Calcium (primarily) and magnesium are the minerals involved in GH, and calcium will dissolve from rock, gravel, or sand that is composed of calcareous mineral like limestone, marble, dolomite, aragonite, coral, shells, etc. The white bits of the substrate could be such a calcareous material. The chunks of rock might be involved as well.

Water conditioner is not going to impact GH/KH/pH.

If you want softy water, presumably you intend soft water fish species. The substrate will likely need to be changed, or the rocks removed. You could do a test on these to see which is the culprit. In a clean bucket of tap water, place one or two of the rocks. In another clean bucket of tap water, put a couple cups of the substrate but rinse it thoroughly under the tap before putting it in as you do not want it contaminated (so to speak) by the tank water. After a day, or two, or three, check the GH in the two buckets.

Makes sense okay I’ll give it a shot. I really hope it’s not the substrate that’s gonna be a nightmare

 

[Naughts]

KH and pH are on the high side, does your home have a water softener that would bring down the GH?

 

[Seb2502]

KH and pH are on the high side, does your home have a water softener that would bring down the GH?

Yes that’s the weird thing
The tap water is soft but once it’s in the tank for a bit it becomes hard somehow

 

[Byron]

Do you have a water softener? This is another whole issue.

 

[Essjay]

You could do a test on these to see which is the culprit. In a clean bucket of tap water, place one or two of the rocks. In another clean bucket of tap water, put a couple cups of the substrate but rinse it thoroughly under the tap before putting it in as you do not want it contaminated (so to speak) by the tank water. After a day, or two, or three, check the GH in the two buckets.

I would also add a third bucket with just water in it. It gives something to compare the water with rocks and water with substrate to. Then you know for sure that any change is due to the rocks or substrate and not something weird in the water itself.

 

[Seb2502]

I would also add a third bucket with just water in it. It gives something to compare the water with rocks and water with substrate to. Then you know for sure that any change is due to the rocks or substrate and not something weird in the water itself.

Makes sense will do thanks!

 

[StevenF]

How often do you do a water change in your tank and when you do how much water do you replace? Water will evaporate from your tank leaving minerals behind. Over time this can make the water hard in the tank especially if you do minimal water changes.

Generally calcium and magnesium mainly dissolve in low pH acidic water. With your high PH and KH I would not expect to see much coming from your substrate.But perform the test others have suggested above to be sure.

Generally you would expect GH to be higher than KH or GH and KH to be about the same. in nature you rarely see very low GH i and a high Kh. Home water softeners use salt to remove calcium and magnesium from the water but in the process it leaves behind sodium bicarbonate which increas PH and KH. Sometimes utilities will add sodium bicarbonate to water to increase PH to minimize water pipe corrosion. Either way very high sodium levels can make your fish sick and possibly kill then slowly or suddenly. i would suggest looking for your utility water quality report it might tell us what the sodium levels are and what the water source is.

 

[Seb2502]

How often do you do a water change in your tank and when you do how much water do you replace? Water will evaporate from your tank leaving minerals behind. Over time this can make the water hard in the tank especially if you do minimal water changes.

Generally calcium and magnesium mainly dissolve in low pH acidic water. With your high PH and KH I would not expect to see much coming from your substrate.But perform the test others have suggested above to be sure.

Generally you would expect GH to be higher than KH or GH and KH to be about the same. in nature you rarely see very low GH i and a high Kh. Home water softeners use salt to remove calcium and magnesium from the water but in the process it leaves behind sodium bicarbonate which increas PH and KH. Sometimes utilities will add sodium bicarbonate to water to increase PH to minimize water pipe corrosion. Either way very high sodium levels can make your fish sick and possibly kill then slowly or suddenly. i would suggest looking for your utility water quality report it might tell us what the sodium levels are and what the water source is.

I don’t do water changes too often maybe once every 2-3 weeks. When I do, I change about 20% of the water

 

[sparkypenguin]

I'm only a newbie but what I found was that unless your tank results are matching your tap results across the board then it's best to do lots of smaller regular water changes. This minimises the variation in the tank results. I do approx. 7% (as this is a bucket) every night and since I started doing this my results have been far more consistent and once they are consistent then you know what you are working with. In your case I would think that by adding 20% every 2 to 3 weeks is quickly changing the water chemistry which is not ideal for the fish. Also note that PH is logarithmic. However you can change the hardness by various methods and pretty much everything currently in your set up or new introductions to your set up could be affecting the hardness etc.e

I also found that a daily water change is actually much easier. I fitted a home brew tap to a bucket which I fill every night with water. I then prime the water and let it drip into the tank overnight. This minimising any changes and negates the need to heat the tap water. I also fitted a pipe and valve to the end of my filters return spray bar which allows me to drain water directly into a bucket without disturbing the tank. it takes about 3 minutes of my time per day.

As previously suggested do a few tests in buckets and also find out what your water authority results are and if they are adding anything to increase the PH which may dissipate over time.

I would also suggest, although other may disagree, getting one of the NTL or API testing kits. These come with test tubes etc and I believe are more accurate.