High KH and low GH - something new to worry about?

My tank has been established for several years and although the fish have been largely OK, I struggle to grow plants.
It is 170l and stocked with a mix of tiger barbs, black ruby barbs and peppered cory.
Today i thought i would test the KH and GH which i haven't done before.
My KH is sky high - using the API drop kit, it needed 24 drops - which apparently means a KH of 24
The GH is very low - really only needed 1 or 2 drops. So very soft water.
My PH is rock solid at 7.6 and never varies.
We are on a borehole in the SW of the UK. There is an inline water softener.

Do i need to worry? Is this why my plants won't grow properly - i am adding API leafzone weekly.

It is possible that i can 'turn down' the water softener. The incoming supply from the borehole is 380ppm (about 22 drops) so the softener is removing a fair amount. If i can do that, then would that affect the KH?

another plan would be to use (say) 15% of unsoftened water to 85% softened. this would give me a GH of around 3 or 4. Might that be better? KH would be the same though.

This is all a bit of a mystery to me. Do i need to worry at all?
Any comments?
Thank you
Ian

 

First off.
What is the parameters of your supply source of water? GH, KH, pH, ammonia, nitrites nitrates.

Next, what are the parameters of your tank water? Same tests.

Apples to apples to see the differences.
Ideally a GH or KH that falls between 4 and 8 degrees is fine. A KH of 2 degrees or below can cause pH fluctuations, above 20 can cause a hard water type situation with too much carbonates and bicarbonate. KH is more about pH stability. If pH is unstable, life in general has a hard time adjusting leading to heath problems.

GH also 4-8 degrees. If too low it can be short in calcium, magnesium or other things, if too high it can be too heavy with them, this is more about general health of plants and animals compared to KH. Too low and fish or plants get deficiencies, too high minerals causes health issues also.

You don't want either going below 2 degrees or above 20 degrees.

If you can compare your softened water to the source water before softening, you can maybe see what the hardness issue is that is being corrected to determine if the softener is set correctly or not. I don't recommend just messing with it without knowing if it's right or wrong because you might just make it even wronger and possibly that just what it can do with the source water.

I think the softener is removing iron, calcium, magnesium ect. And the process is what's pushing the KH up which in theory, maybe with salts it isn't a bad thing for human consumption, but would be bad for plants. The pH would be stable. But higher salts and carbonates.

There may be adjustment that could be made to bring GH up to 4 and KH down by 2-4... but I'm not sure because I don't know what it starts as and what it's doing, and I don't know what your well established tank is doing compared to fresh drawn water from your source. Might want to bring someone in to test the well, very possible there's something there that's hazardous and the reason for the softener I don't recommend messing with it unless you know it's going to remain safe.

Anyways, it's a starting point on what to look at to determine the issue, and how much correction it needs.

Where it stands you could use distilled or ro/di water and 50/50 to lower KH but GH would go down with it and you don't want that going lower.
You could skip that water and distilledro/di mixand go with ro/di and build your water up to proper parameters you want orgo with bottled water that tests where you want it to be.

You can also set up a cistern and collect rain water for your tanks and test it to see what ammendments needs to be made and store the rain water for water changes. It may also need mineralization.. a slight bump of calcium and magnesium and potassium to bring up GHand 50/50 with your softened water to cut the KH to 10 and bring the GH up to 10. 10s should be safe for the plants and fish.

Really have to know what your dealing with before treatment, after, and then tank, to decide the best, and cost effective way to manage it.

 

If you have hard water and a water softener, this is what you'll see. Out of my tap (which comes from the softener) I have GH of 1 and KH about 16. I just add a GH booster with every water change to keep GH around 5-7.

I use Thrive GH boost but there are other brands too.

 

Plants hate water that comes through a softener like this. Many folks install a bypass line for the softener and use the hard water for the plants/aquarium successfully.

 

First off.
What is the parameters of your supply source of water? GH, KH, pH, ammonia, nitrites nitrates.

Next, what are the parameters of your tank water? Same tests.

Apples to apples to see the differences.
Ideally a GH or KH that falls between 4 and 8 degrees is fine. A KH of 2 degrees or below can cause pH fluctuations, above 20 can cause a hard water type situation with too much carbonates and bicarbonate. KH is more about pH stability. If pH is unstable, life in general has a hard time adjusting leading to heath problems.

GH also 4-8 degrees. If too low it can be short in calcium, magnesium or other things, if too high it can be too heavy with them, this is more about general health of plants and animals compared to KH. Too low and fish or plants get deficiencies, too high minerals causes health issues also.

You don't want either going below 2 degrees or above 20 degrees.

If you can compare your softened water to the source water before softening, you can maybe see what the hardness issue is that is being corrected to determine if the softener is set correctly or not. I don't recommend just messing with it without knowing if it's right or wrong because you might just make it even wronger and possibly that just what it can do with the source water.

I think the softener is removing iron, calcium, magnesium ect. And the process is what's pushing the KH up which in theory, maybe with salts it isn't a bad thing for human consumption, but would be bad for plants. The pH would be stable. But higher salts and carbonates.

There may be adjustment that could be made to bring GH up to 4 and KH down by 2-4... but I'm not sure because I don't know what it starts as and what it's doing, and I don't know what your well established tank is doing compared to fresh drawn water from your source. Might want to bring someone in to test the well, very possible there's something there that's hazardous and the reason for the softener I don't recommend messing with it unless you know it's going to remain safe.

Anyways, it's a starting point on what to look at to determine the issue, and how much correction it needs.

Where it stands you could use distilled or ro/di water and 50/50 to lower KH but GH would go down with it and you don't want that going lower.
You could skip that water and distilledro/di mixand go with ro/di and build your water up to proper parameters you want orgo with bottled water that tests where you want it to be.

You can also set up a cistern and collect rain water for your tanks and test it to see what ammendments needs to be made and store the rain water for water changes. It may also need mineralization.. a slight bump of calcium and magnesium and potassium to bring up GHand 50/50 with your softened water to cut the KH to 10 and bring the GH up to 10. 10s should be safe for the plants and fish.

Really have to know what your dealing with before treatment, after, and then tank, to decide the best, and cost effective way to manage it.

Thank you for your detailed reply. Our well water is tested by the local authority and no problems have been found. Last time tested they found NO3 at 22. Though my more recent figures have been 15 to 20.

The parameters are as below. bearing in mind that its difficult to be exact when the colour changes when adding drops for KH/GH test.
Ammonia and Nitrite are both 0.
My water is Nitrates 20 direct from the tap.

	PH	KH degrees	GH degrees
Well water via softener bypass	7.6	21	25
Tap water via softener	7.6	21	1
Tank water	7.6	20	1

I would like to get GH to around 5. That would then be a 20% mix of pre-softener water to softener water, so in my 170l tank would need 34l of bypass water.
I plan to gradually get to this by adding a few litres of bypass water at a time. I have this morning added 6l of bypass water and will add 6l tomorrow and so on until i have added enough to get to GH 5 degrees. Then when i do subsequent water changes, i can keep that water at 20% also.

I will just live with the high KH - guess thats not a problem?

Is that a workable plan?

 

Thats awesome information and yes, likely doing that will work. Just keep and eye on your pH, it shouldn't drop out but it might rise upward and become more and more alkaline.
It looks as if the pH is right about where it needs to be, before, during and after. I don't think it should go up higher by raising the GH, but I'm not sure so be wary of that possibly happening.

The KH can be a problem being alkaline, it wouldn't hurt as it neutralizes acids produced by nitrates and gas exchange ect. But you might have problems with spawning/breeding or shorter life spans with the fish if it's too far out of comfortable range for the species kept.

Rainwater falls somewhere in a pH6-7 and a KH and GH from 0-2 degrees. If you used that on a 75-25 with your bypass water you should in theory be somewhere around 5-7 for GH and KH and I don't think the pH changes, but might drop a few points just from becoming more neutral over all and closer to pH7. Just a thought if you wanted to experiment with that and a bucket and see what's possible there to lower KH, raise GH and see where pH ends up at see if it's worthwhile to go further to collect and store in the yard for the tank.

 

That's really helpful, thank you

 

If you're going to go all testing crazy (like me), you have an option that many don't think of. I run my planted soft water tanks "intentionally depleted".

The basic ingredients you need to use to run a depleted tank are calcium chloride (calcium/GH), magnesium sulfate (magnesium/GH), potassium bicarbonate (potassium/kH), and iron. You could substitute potassium sulfate (potassium/neutral) instead of the bicarbonate since you have plenty of kH.

Use rotalabutterfly or a similair nutrient calculator (or some legitimate chemistry equations) to calculate dosage of each, then do some testing in a bucket any time you get a new batch of ingredients to verify/calibrate.

Hard part is depleting the initial kH and nitrogen from your tap. You can eliminate the nitrogen through removal of plant matter/rapid growth. Stabilize the GH side with the mixture of calcium and magnesium (potassium also if you get the potassium sulfate, I would recommend that in your situation). Try to balance your additional calcium: magnesium: potassium ratio at something close to 3-5 parts Ca:1 part Mg: 3-5 parts K. You can adjust this as you see any issues in leaf production. Try to lock n: p: k at 20:1:8 but most important (I've tested, researched and debated this but heres what I think as someone who does run fully depleted tanks and adds everything) keep your nitrogen: phosphate ratio stronger than 18:1. You can also go lower than 7:1(or even high phosphate, nitrogen limited) but in the middle (11:1 etc) you will get excess growth of certain algae rapid enough to out compete your other plants. Since you are starting with high nitrates, and will be depleting your water through nitrogen conversion and plant growth it would be hard to keep the ratios in check running a high phosphate ratio.

Hold water changes, test regularly and add a stock solution of GH/minerals as needed while removing plant matter over a good amount of time and you should be able to deplete the kH into the low teens, or even high single digits fairly easily. As long as your tank is burning more nitrogen through growth than the fish and top off water are providing you should be set. Once depleted you can go to it with easy math water changes, if tank is at 10kh, tap is 21, a 50% gives you just over 15kh, then monitor for time to use 5 kH, and you figure out your water change intervals.

Unorthodox, but effective in most heavily planted and moderately stocked situations I've encountered. It gives you a way better idea of what's in your water than just using an off the shelf buffer product and in my experiences offers the best way to get what you actually need in the tank, not what someone else needs on average(that's what they sell, average use case products, and your use case is not average).