Raising KH without pH

[yudhas]

Hey guys,

Here's the story. When I was cycling my tank (fishless), my pH was swinging like it was the 1940s. It went as high as 7.2 and as low as 6.4. So I decided to check the KH, it turns out it was only 2. Since there was no fish in there, as I was still cycling, I put some Seachem Alkaline Buffer which raises the KH to 5 and my pH to 7.6. It stabled out.

After my cycle completed, I did a major water change which in turn dropped the pH to 7.0. I've tested my water here and the pH is 7.0. I've slowly stocked my tank and now there is 12 platys/swordtails (ratio of 3M:9F). The pH have been stable at 7.0 for the past 5 days and occasionally goes up to 7.2. I thought this is great my buffer is still there. But it turns out that my KH is actually at 1.

So my question is should I increase my KH to protect my pH from swinging or should I just leave it as it is? If yes, how do I do that? The alkaline buffer will definitely raise the pH as well.

Thanks

PS. my tank is 85 gallon

 

[Coryluv]

Welcome to the joys of water chemistry. Are there other fishkeepers in your area? What do they do? What is their experience with their tanks? Do you have a local shop you can consult with? That's where I'd start.

I don't have your particular problem and hesitate to make recommendations for your situation. My tap has a KH of 5 and my tank has a KH of 4. Those aren't all that high, but they are enough.

What is your GH btw? It is possible that you have other buffers in your water. I'm pretty sure I do. My GH is 11 and my pH is very, very stable at 7.8.

Raising the KH will raise the GH. Carbonate hardness is a component of General Hardness.

 

[anteatergoanna]

I have 0 KH and have for a long time, my PH stays between 7.1 - 7.3 .... "If it ain't broke don't fix it" is what I have been told. I haven't done anything and it is still the same.

 

[yudhas]

Well my GH is at 5. I checked my water source's KH and is at 1. And the problem is that my tank is relatively planted and if I use one of those charts for pH and KH to determine my CO2 levels, I'm way below the optimal level. Unfortunately I can't afford a CO2 system yet and it won't be for a while. I don't want to use a DIY system as I know I'm going for the full system eventually, so at the moment I'm ordering Flourish Excel which hopefully will help it a little bit.

But are Flourish and Flourish Excel will kill my fishes?

 

[Brookster123]

Flourish will not kill fish, just dose up to recommended levels gradually over a couple weeks..

Sent from my SAMSUNG-SM-G900A using Aquarium Advice mobile app

 

[Coryluv]

Well my GH is at 5. I checked my water source's KH and is at 1. And the problem is that my tank is relatively planted and if I use one of those charts for pH and KH to determine my CO2 levels, I'm way below the optimal level. Unfortunately I can't afford a CO2 system yet and it won't be for a while. I don't want to use a DIY system as I know I'm going for the full system eventually, so at the moment I'm ordering Flourish Excel which hopefully will help it a little bit.

But are Flourish and Flourish Excel will kill my fishes?

I use Flourish Excel and Comprehensive without problems.

As to CO2, yes it changes the pH but it's more complicated the that. The minerals that make the KH and GH are still in your water so it doesn't affect the fish the same way adding or removing the actual minerals would. I am not an expert on this. I'm only gathering materials for a DIY CO2 system now. If that is your concern you might try asking that question over in the Planted section where the experts on that hang out.

 

[Delapool]

Well my GH is at 5. I checked my water source's KH and is at 1. And the problem is that my tank is relatively planted and if I use one of those charts for pH and KH to determine my CO2 levels, I'm way below the optimal level. Unfortunately I can't afford a CO2 system yet and it won't be for a while. I don't want to use a DIY system as I know I'm going for the full system eventually, so at the moment I'm ordering Flourish Excel which hopefully will help it a little bit.



But are Flourish and Flourish Excel will kill my fishes?

Gh and kh can be unrelated over time. Over summer my kh does the same in that it is about 2 or 3 but I'm lucky tap is 4 or 5.

I've added seashells or crushed coral as a long term fix but I think here it is more if the ph drops below 7 as otherwise it doesn't help enough for me. Basically calcium carbonates though. Probably if it was crushed finer would help. If my tank ph crashes this is my back up.

I use a kh buffer as well which is probably baking soda (sodium bi carbonate). I've dialled that in and add a little each week without much ph increase. Lots of kh tests though as my tap water kh changes through the seasons. This should be ok with plants. I did ask here and was told it would be ok and so far all good.

I have looked at trying to get potassium carbonate (link below) which apparently will not increase ph. The only place I found here was pretty expensive at almost lab quality so I never ended up getting any to test.


http://www.theaquariumwiki.com/KH

 

[yudhas]

I read about potassium carbonate as well but where I live, is impossible to find it. Plus I wouldn't know the right amount to put in the tank.

What about using both Seachem alkaline and acid buffer to control the pH? Is that worth it? Have anybody tried it? And is it safe for the fishes if I dose it straight onto the tank?

Thanks

 

[Coryluv]

I read about potassium carbonate as well but where I live, is impossible to find it. Plus I wouldn't know the right amount to put in the tank.

What about using both Seachem alkaline and acid buffer to control the pH? Is that worth it? Have anybody tried it? And is it safe for the fishes if I dose it straight onto the tank?

Thanks

Since intended consequences can occur, most of us don't try to control the pH.

If you decide to go the Seachem route, follow the instructions. I'd mix it in a bucket first. Make any changes very slowly. Seachem makes quality products, but I have not used those products, nor would I unless I had a real reason to do so.

However, it is much better not to mess with it if you don't really need to. There is an old saying that applies: If it ain't broke, don't fix it.

 

[yudhas]

I should've said in order for me to increase the KH but at the same time not increase the pH drastically should I mix the two buffers.

I know that alkaline buffer increases buffering capabilities but at the same time increases the pH. I want to keep my pH as it is at a good level already. However I'm afraid of swings as I practically have no buffer.

But I think you're right. I probably won't do anything unless I have a huge pH crash.

 

[Coryluv]

I understand your concern with your KH. If all I wanted to do was increase my KH a little, I'd just carefully use a VERY small amount of baking soda and accept a small pH increase. I'd mix it in a bucket of tap water, and use it during small water changes over time to slowly raise the KH. That's strictly what I'd do, not what I'm telling you to do.

As to Seachem buffers, study the Seachem website and/or email them directly to see how to use their products to do what you want to do (raise KH without raising pH). They really are the experts on their products. It's tricky and no advice is better than bad advice.

Even better just continue to do your water changes and housekeeping to keep the organics that can cause a crash to a minimum.

 

[Delapool]

I read about potassium carbonate as well but where I live, is impossible to find it. Plus I wouldn't know the right amount to put in the tank.

What about using both Seachem alkaline and acid buffer to control the pH? Is that worth it? Have anybody tried it? And is it safe for the fishes if I dose it straight onto the tank?

Thanks

I wouldn't bother with both seachem products although it needs someone smarter than me.

It says 'As Acid Buffer™ lowers pH it converts carbonate alkalinity (KH) into available CO2. It may also be used to safely lower pH in marine water.'

So I suspect you could be just neutralising your newly added alkaline buffer.

Whichever way you go I found that you can't just work out say a baking soda dosage or buffer ratio and 'set and forget'. You have to test a lot. In mine it is basically a tweak to go from say 2 to 4 (or maintain the 4 kh) which is still soft and I didn't find a lot of change occurred in ph. I started off small doses and then went up to where it would hold kh/ph rather than trying to increase it. So I guess for me that is why the testing was so important.

 

[pip walters]

You can increase the KH (buffering capacity) by adding calcium carbonate. 1/2 teaspoon per 100 litres will increase KH by 1 or 2 degrees. You need to be careful when increasing a KH that is already less than around 4.5dH so it would be best to mix the required amount of calcium carbonate in a bucket of water first, then drip it into the tank over as long a period of time as you can, testing the pH regularly.

KH of 4.5dH or more can be raised by adding calcium carbonate, with little effect on pH. The pH will then remain stable as long as regular water changes are maintained to remove nitrate, which is acidic. Water added during a water change should be of the same KH as that required for successful buffering in any one system and this will depend on the amount of nitrate being produced. Adding broken sea shells, coral etc should have the same effect and should be a more gradual approach.

Adding baking soda will increase KH, but will also increase pH, which will eventually stabilise around 8.2.

Hope that makes some sense!

 

[Delapool]

Hi Pip, in your experience have you looked at when the impact of crushed coral on ph tapers off? I've added it to the tank but ph sits around 7.4 already sooo doesn't seem to do much. Not sure to just keep adding more?

 

[trennamw]

I have had a terrible time with alkaline buffers to stabilize pH in soft water.

For me, small doses of cichlid salts and cichlid buffer - enough to get KH and GH above 3 - have given the most consistent results. Consistency is the goal after all, not a precise pH.

Crushed coral had helped some too for KH but I had to use a ton. Seachem equilibrium has been unpredictable too for GH. I water change often enough the cichlid products have been ok. And my fishes happier behavior with the cichlid products (along with the nutrients in the fish food) mean I'm no longer swayed by seachem's claim that their wider assortment of minerals is better.

Now I just wish I'd used Epsom salts and baking soda instead of the expensive API cichlid products, it's pretty much the same lol.

The recommendation for the buffered cichlid salts came from a fish book by Boruchowitz, for soft water even when not keeping cichlids. Again, it's a smaller dose than for cichlid tanks.

 

[Delapool]

Yes, I find seachem a bit forward sometimes

I've picked up a bottle of calcium carbonate liquid that was really cheap but saving that for next summer. I'll have to load more seashells into the filter and crush them up better. Sounds like I'm a bit light on there.

I did collect a heap of cuttlebone over Christmas and that was easy to crush up. But the darn stuff floated around the tank for weeks - really annoying.

Who knew fish keeping was so relaxing