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3122 Views 9 Replies 5 Participants Last post by  drbdc

I have a couple of questions regarding my KH & GH levels. My lvl of KH is nonexistant. I understand this can be raised by adding baking soda to the water when I do water changes.

In a 10 gall tank, I should be adding a 1/4 tsp per gallon, per water change to slowly up it? Is that correct?

To raise the GH (which I believe is around 80ppm) I add a source of calcium chloride. I would prefer to do this in a more natural manner. Would adding a fist sized chunk of Tufa rock, or a chunk of dried coral achieve this end? A gradual upping of the GH? Or would that cause my GH to spike up quickly? I do weekly tests on my water, so I would ASSUME that I would catch it as it rises, & be able to pull it out when its reached the level I want it at, then replace it as needed..... But thats an assumption, & I wanted to come talk to the pros first.

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Adding the bicarb slowly is the way to go. It will increase the pH as you do it, which fish never like. The slower you do it, generally the safer it will be for your animals (and plants). You fish will also appreciate the fact that a higher KH will hold it's pH better and is less subject to rapid swings.
As for the GH, adding a source of calcium will slowly raise the GH. Shells and some rocks are generally the preferred way of doing it slowly. The more water movement you have around the rocks/shells, the faster they will dissolve. Also, they will dissolve faster in more acidic water, so if you want to increase the GH slowly, first bring up the KH.

I adjust my KH for my 90 gal. 2 tsp. at a time. pH on my controller goes up from 6.5 to about 6.9, then wait for the pH to drop (about 5 min.) then add another aliquot until I reach my targel level. You might go with a bigger pH swing with no problems, but this is the way I've been doing it.

As for raising your GH proposal. What is natural about raising your GH in a freshwater tank with reef remnants, especially if you already have CaCl2? Sounds like more work (adding the rock, monitoring the GH levels and pulling it out) than just adjusting it with CaCl2 and leaving it. That's just the way I'm lookin' at it.

Anyone else?
Gill, do you just add the Baking Soda to your water already in there, or do you mix it then dump it in?

Where can you buy Calcium Chloride over the counter?

Unrelated to the topic, what is the ligthing on your 90 gall?

Thanks for the replies!
Hi travdawg

travdawg said:
Where can you buy Calcium Chloride over the counter?
You can buy some from Greg Watson he is an APC sponsor. Also pool supply stores have it as well just be sure that it is pure Calcium Chloride and there are no other additives.

I just mix it in a glass with tap water, and, depending on how I'm feeling, I either drink it or pour it into the tank. :smile: My tap water is only 1.5 dKH, so when I do a 70% water change, I have to add about 4 tsp of baking soda. I add 2 at a time and wait for my pH to adjust back down before I add the second. If I drink it, I just belch, then make another batch for the fish. If they belch, it's not a good thing! :smile:

I use CaCO3 so I can measure my levels with my test kit, which is specific for CaCO3. Yes, CaCl2 or CaCO3 from GW.
I have been putting off an order to GW for awhile now... But I guess one is looming now ever closer!!!!
Well, Iw as gonna order from Greg, but the shipping for 1lb of the product brought the order up to like $11. So I called a local pool supplier & they have a Calcium Hardener, but it also has Sodium Chloride in with the Calcium Chloride. I assume that is bad?
CaCl can be purchased at many Home Depots very cheap. It is produced by Dow Chemical and sold under many names. The version marketed as Dow flakes has been chemical analysed by Dr. Randy Holmes Farley and determined safe for reef tanks as well. It is also sold in a pellet form under other names. I use Prestone Driveway heat which is 10% stronger than the Dowflakes due to less water content in the pellet form. To make a mixture I use 1 cup prestone per gallon water, that will change the ppm of ca by 10 using 204ml per 100 gallons. For the alk part I use 1 1/8 cups baking soda per gallon water and 142ml per 100 gallons changes dKh by 1.

Here is a handy calculator for dKh, ca, and magnesium. My mixtures are using the "Randy's recipe 2"
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BTW, down under notes when it talks about lowering or raising pH, it is from the baseline of 8.3 on saltwater tanks. Obviously adding baking soda to a tank around 7 will raise the pH even though it shows on the calculator notes that it will lower it.
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