Some pH/KH experiments....

yhbae

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Aug 5, 2003
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In search for the solution on how to add some buffer without raising my pH to extreme levels, I performed some experiments earlier today...

My normal water parameter after 24 hours:
- pH : 7.0
- KH : 2dH or less
- GH : 5dH

I found a piece of driftwood that I soaked for just over a week. I see much less tan color leaching now...
The water parameter of the sample that came from the driftwood soaked bucket:
- pH : 6.2
- KH : 1dH or less!
- GH : I don't care... :D

I took a cup of this water, added minute amount of baking soda. At first I over-did it, and pH shoot to 8.0... :D

Threw that one away, and did it again. This time I have:
- pH : 7.8
- KH : 5

So I hoped that if I mix this water with more water from the driftwood bucket, perhaps I may be able to find the balance that gives pH 7 and KH greater than 2.

So here I went and mixed them until I got pH of 7.0. Then with ultra-hopeful feeling, I measured KH... It was just under 2.0.. So I'm back to square one... :D

So to put long story short, adding baking soda & driftwood with the intention of increasing the buffer without increasing pH doesn't work... :D
 
Great job on your experiments! I want to give you props for even taking the time to try and figure things out for yourself, and then again, for placing those findings on the forum for the rest of us!

I have hypothesised that this would be the outcome, but have never tested it for myself. We really appreciate your effort.
 
Thank you for the kind words... Wether it is useful or not, I do enjoy experimenting with these theories... :D

Do you know if there's any other solution?

According to that article, one other way I can achieve what I want is to "add" more CO2 to my water. (So I would need to add either baking soda or cushed coral and inject some CO2). I have to admit that with only 3 fishes in 25g plus decent amount of java moss plus Aqua Clear 200 set at max flow (lots of bubbles near the filter!) won't help retaining the level of CO2... I hope that by the time the tank is fully stocked, fishes will produce more CO2...

I don't like it - I already experienced a sharp drop of pH by 0.4 over one night... :( Perhaps I should try to reduce the level of flow of the filter? It must be at at least 8x (if not 10x) per hour right now...
 
The main problem with adding crushed coral, or KH altering gravel, is that as you do things to lower the pH of the water, the crushed coral dissolves even faster......and raises the pH even higher!

I tried adding crushed coral to my tank (with CO2 injection), and even with minute amounts in the filter, the KH went to well over 6 (close to 7). It would have continued to rise if I had left it in! It will eventually equalibrialize (is that a word?) but at a higher level than I was wanting.
 
I don't really know what the solution is at this point other than frequent water changes... I guess frequent water changes will overcome just about any water chemistry related problem, especially if you have tap water that is as "neutral" as mine... I guess for the next forseable future, I'll continue to do bi-weekly 20% water change even when the tank is fully cycled...
 
yhbae,

I can understand the desire to elevate the KH, but is there a specific reason you want to have 7.0 pH? Unless you are trying to breed fish, the pH isn't really that critical.

PP
 
In simple terms there is no way you can increase KH and keep your pH low without CO2 injection. (Actually there is but it is too much work even for a chemist like me).

On another note, trying to increase KH is not a good thing for many species. our water here has a KH average of 0.8 and I don't tinker with it apart from the mixed fertaliser I add which contains a little bit of phosphate which keeps the pH from droping too low. My tank is 150G and pH generally stays between 6 - 6.5

I do however have to add a little bit of Bicarbonate to the 10G as the pH drops below 6 on occasions but I only need to use a bit on the tip of a spoon and that does the job....
 
Originally posted by Pink Pat
yhbae,

I can understand the desire to elevate the KH, but is there a specific reason you want to have 7.0 pH? Unless you are trying to breed fish, the pH isn't really that critical.

PP

I guess the reason for my effort in keeping pH at 7 (while increasing KH) is due to the fish selection that I ended up with for this community tank. I think most will be fine at 7.2 or even 7.4, but I am hving a hard time keeping it below 7.6 with KH greater than 2...

Yes, I'd be happy if I can increase KH without increasing pH too much above 7... pH of 7.6 seem little high for some species (such as Cardinal Tetra).
 
Originally posted by a_free_bird73
In simple terms there is no way you can increase KH and keep your pH low without CO2 injection. (Actually there is but it is too much work even for a chemist like me).

On another note, trying to increase KH is not a good thing for many species. our water here has a KH average of 0.8 and I don't tinker with it apart from the mixed fertaliser I add which contains a little bit of phosphate which keeps the pH from droping too low. My tank is 150G and pH generally stays between 6 - 6.5

I do however have to add a little bit of Bicarbonate to the 10G as the pH drops below 6 on occasions but I only need to use a bit on the tip of a spoon and that does the job....

Yes, adding CO2 seems to be the only option left for me... (Wether it happens naturally or artificially is another story though...)

I will eventually try to breed every species I have in the tank - I guess this water will be very appropriate for that purpose... :D I already bought another used 33g tank for growing fries, and am shopping for a used 10g for breeding/spowning. Been reading breeding articles on various species and it is very interesting indeed!

So in summary, I currently own in total, 3 platies and two tanks worth 58g of water. Ouch... :D
 
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