KH to low

[jc63]

Hi, I'm new to simply discus and this is my 1'st. post.I have been reading so much on the boards and I am overwelhmed by all the info.I have so many questions and I have found the answers to many of them by reading the boards.This is my question? How can I raise my KH without raising my GH and PH?
My tank is 65 gal.36x18x24.,2"sm gravel/latterite mix substrate,many rocks, 2 lg pieces driftwood,and lots of plants.Tank water ;amonia-0,nitrite-0,GH-8.5,KH-1,PH fluctuates between 6.3 to 7.3. I do water changes 2 to 3 times a week of 20,25gal by bucket.I use NovAqua tapwater conditioner by kordon in my water changes.I ad instant amazon 2tbs wkly: 5 tsp botanica grow,1tsp botanica K,1tbs fourish trace,6mls flourish iron wkly.

Lighting 110wat compact strip 1-55w 6700 & 1-55w 5300 :1-30w power glo light.
Fish 4 Discus(3@4+in,1@6+in),3 silver hatchets,4 rummynose,1 one-eyed cardinal tetra,5 corys,6 ottos,2 whiptails.
If I left anything out that might be important, I'll post it.
Thanks Shawn B.

[Debbie]

You could put a bag of crushed coral in your filter. The crushed coral would slowly dissolve raising your KH enough to buffer your water so your pH wouldn't fluctuate so much.

[ChloroPhil]

Welcome to Show Tanks and Biotopes JC! It's good to have a new face here.

I'm going to reply to your questions with a few of my own.

Are you supplimenting with CO2? That's about the only way you can increase KH without upping your pH.

Baking soda works really well as a KH buffer, so would Botanica KH.

Best,
Phil

[jc63]

Thanks for the responses.I do not use co2.I am considering trying it but I'm not familiar with the process.I will research.
I have tryed the Botanica KH and was unsuccessful.It raised my ph to 8+ and my KH to 2dh.I have not tryed crushed corel or baking soda.Will this raise the GH and PH? Also at what dose should I use to raise the KH to 3 or 4 dh?
Water out of the tap:
amonia- 1.0 ml/l
nitrite- .5 mg/l
GH- 8dh
KH- 2dh
PH- 9+
As far as CO2 I have started to use natural aqarium vital by Marc Weiss at 1tbs daily for 8 days now.So far I have only noticed that my ph has droped but it has always droped.GH and KH have stayed the same.I am considering using saecrams flourish excell.Open to advise.Thanks Shawn B.

[ChloroPhil]

JC,

If your KH is 2.0 dKh I wouldn't worry about upping it. That's really enough. My tap comes out at 1.0 or so and I don't buffer any more than that. I've got a really good needlevalve and CO2 system though, so I don't have to worry about that too much.

If you're set on increasing KH use 1 tablespoon of Baking Soda for every 100g for an increase of about 1.0dKh. Baking Soda is Sodium Bicarbonate and won't affect GH, it'll only increase the Carbonate Hardness (KH) of your system.

It WILL affect pH though. An increase in KH naturally raises the pH through buffering of pH reducing acids in the water. If you're not adding CO2 (which acidifies the water) don't increase your KH.

Best,
Phil

[Nightowl]

There is a product by Hagen called PH stabilizer/KH booster that claims to raise KH without raising PH.
If you add coral to a tank you will definitely raise the GH. I have a 15g Af. cichlid tank w/ a few coral skeletons in it( about1.5 lbs). The KH is 4 degrees...the GH is 27 degrees!
As already stated, its hard to raise KH without raising Ph because when you add carbonates you "use up" acids. Sometimes you have to use a carbonate booster with an acidifier(premixing water outside of the tank of course) to achieve the KH and PH that you desire. That's what products like "proper ph 6.5" are... a blend of PH uppers(carbonates & bicarbonates) and PH lowerers (acids), blended to achieve a certain level.
Your Ph will probably continue to fluctuate when your KH is only 2 degrees. I use Kent African cichlid buffer in my 125 g tank... but its very potent and can raise ph in a hurry. I find that just a half teaspoon can set the tank right if the ph has gotten a bit low. It is a KH booster so things hold for a while. Of course, nothing beats daily water changes with perfectly balanced water but......
You need to achieve a KH of 4 degrees to stabilize your PH. Coral works, but not without raising the GH as well. Good Luck! J.T.

[ChloroPhil]

Ok, let me see if I can get the chemistry of this down here:

You add {CO3 (2-)} [Carbonate] to water containing acids (H+) and you get Bicarbonates out of it (HCO3)

CO3(2-) + H+ = HCO3-

By bonding the acids to the carbonate you're going to make the water less acid, by definition increasing the pH. There is no way of increasing Carbonate Hardness (KH) without a corresponding raise in pH, no matter how small it is.

In aquariums with CO2 enrichment you're going to get something like this:

H2O [liquid]+ CO2 [gas] = H2CO3 (carbonic acid) [aqeuous solution]


H2CO3 = H2 + CO2 + O <- Photosynthesis

That free Hydrogen is going to react with the available carbonate in the water (your KH) and form Bicarbonate; HCO3(-). At some point that Bicarbonate ion is going to break down and the cycle is going to start all over again.

That my friends, is how KH buffers the acidity of our aquariums. Enjoy!

Phil Rye, the Botany Guy strikes again.... ;D

[Debbie]

Phil, looks like you got the chemistry down, I'm impressed. Your right that you are going to raise the pH somewhat if you raise the KH. If the tank is fluctuating between 6.3 and 7.3 it is better to raise the KH (and pH) a little bit. Stability is better than low pH. I use crushed coral, just a small bag, in one of my smaller tanks because that one will drop all the way to 5.0 and my KH is 4 from the tap. It does raise GH to about 6 but at least it keeps the pH at 6.5 and stable and the KH to 5. I did add baking soda at one time but I found that the crushed coral was much easier, no measuring, no adding anything to each water change (except conditioner). Another thing with the crushed coral is that it will dissolve quicker when the water is more acidic to achieve stability. It won't dissolve at all at pH higher than 8.2.

[ChloroPhil]

Debbie,

I'm not paying all this money to the university for nothing. I had better be learning _something_. Nutrient cycling in aquatic systems and aquariums is one of my major interests. If all goes well I'll be doing my minor Ph.D work in Biogeochemistry. We'll just have to wait and see.

[Debbie]

I find chemistry fascinating, took a couple of extra chemistry classes in college myself. I don't use much if it any more so I have forgotten much of what I learned, but do enjoy it when others refresh my memory.