Water Parameter Help Please

Everything you ever wanted to say about "Zebra luvin", but didn't because you thought everyone would take the mickey! Plus general topics for discussion including everything from what you feed them to your personal experiences.

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LyreTail
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Post by LyreTail »

"Kent RO right" does not effect the alkalinity or pH at all. Seachem's "Equilibrium" are the same salts so you can comparison shop. Takes about a tablespoon of these mixes for every 50 US gal to raise 1 dGH if I remember right. Took me while to come up with all the alternative salts to make my own salt mixes. Finally found the Anhydrous Calcium Chloride flake and cheep Potassium chloride salt at my local hydroponics shop to go along with Epsom salt to raise GH with a balance. To tell you the truth I was a little apprehensive trying this at first. Never really saw a difference except in my positive cash flow. :lol:

Glockfu : I believe about 1 tsp of baking soda in 50 US gallon ( 190 liters) raises the KH by about 1 dKH
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Andrew C
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Post by Andrew C »

LyreTail
I also have very soft tap water, pH - 7.6, KH - 1, GH - 1.
For the dwarf cichlids i keep, i add a golfball sized ball of peat to their storage tank, which gives me a pH of 6.0 to 6.5 overnight, and hardly any KH, which is good for breeding them in.
But i do change 50% of the water weekly, and find that fish that come from acidic water are much more able to deal with low KH levels than fish that don't.

I had always read you need a minimum KH of 3 to 4 or you will get pH swings.
So i used to add a teaspoon full of bi-carbonate to the water in a 10G storage tank before water changes, which raised the KH to around 3, but the bi-carb also raised the pH of the water to 7.8, which is no use for acidic loving fish.

Zebras come from THE Rio Xingo, which is a Clearwater river, and has typical water parameters of;
pH - 6.9 to 7.3
dH - 5 to 12
Temperature - 24 to 28 degrees.
So, it is probably better to keep them in higher KH water, even if it does increase the pH.

One thing yhat has always stumped me, is how some people say they have an acidic pH and KH levels of 4 or 5.

How is this done ?
Tom2600
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Post by Tom2600 »

KH does not control the pH level it just provides some stability. Generally speaking the lower the KH the easier it is for the PH to fall.
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LyreTail
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Post by LyreTail »

Actually KH does directly control the pH in the absence of acids.
Otherwise the CO2 charts would be in error as a premise. There is a direct mathematical relationship between KH and pH. The CO2 charts do not compensate for other bases besides bicarbonate/ carbonate and acids beside carbonic acid, so they are not correct but they can get you close in a clean, non black water tank with an absence of Phosphate buffers.

Water with zero KH and heavy aeration and no acids should have a natural pH around 7.0, but the truth is that you can not easily dispell all the CO2 so the pH might actually be slightly lower

To have a higher KH and a lower pH you have to constantly supply acids. As the acids collide with the bicarbonate ions, both get neutralized. This is why you can see a pH crash when most of the KH is used up. Acids are allowed to accumulate without being neutralized.
This is also why a low KH is easier to hold steady with a low pH. Acids take longer to come into contact with bicarbonate ions.

The reason the Rio Xingu may have a slightly higher KH ( but still soft) and a lower pH is humic acid / black water effect due to rotting plant matter. I am no expert at the exact water parameters in the area where these fish are found - seems like some disagree. Apparently it is considered a "clear water river" which can have a very wide range in water parameters depending on the time of year and exact location.

http://www.geocities.com/NapaValley/549 ... 1page.html

http://www.planetcatfish.com/cotm/1997_11.php
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Andrew C
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Post by Andrew C »

The Peat Page is a good article and explains PH / KH / GH well and in understandable terms.
http://hjem.get2net.dk/Best_of_the_Web/peat%20page.html
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LyreTail
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Post by LyreTail »

Some errors on that peat page and some good info. The discussion that peat ( or other nitric and humic acids) does not change CO2 charts is in error. I have ran controlled tests to discover that the addition of acids does ruin the charts just like adding phosphate buffers will ruin the KH part of the formulas.

I am currently working on a pH shift formula to determine CO2 rather than relying on those erroneous charts. Basicly take two pH measurements. One from the tank and one after a sample taken from tank is aerated for sufficiant time to dispell most CO2. Doing this should allow for a correction factor to be placed in the CO2 chart for either extra buffers or extra acids

I have not tested the ion exchange properties of peat, so I can not comment on that. It is something I wanted to run controlled tests on this summer, but ran out of time making too many caves. I have always wondered if this was myth or truth and have seen no scientific controled studies to support some peoples claims
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