dwalstad

Below is the procedure that we worked out (see earlier page of thread below) for increasing the GH using calcium chloride and magnesium sulfate. This procedure is faster and better than adding oyster grit to the filter. It shouldn't increase the pH.

This procedure is designed for very softwater aquariums where GH = 0- 6 and plants aren't doing well)

• Measure starting GH of your aquarium water
  
• Prepare concentrated solutions of each chemical (MgSO4 and CaCl2)
  
• Add a small portion of Mg solution to the aquarium and measure resulting GH increase
  
• Add Mg solution until you get about what you want (I'd recommend a GH increase of about 1-2, no more)
  
• Then start adding the Ca solution until you get a GH increase that is 4X that of the increased GH due to Mg
  
• The final GH should be over 6, preferably around 8

http://www.aquaticplantcentral.com/f...ht=Equilibrium

 

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snowy

Thanks for providing that info, the water in our area is quite soft so this is good to know. I have been using shellgrit in the sump of the filter on one tank and adding a commercial mix of mineral salts intended for hardening RO water to another, but this is a much more accurate and predictable way to do it.

DataGuru

So is someone going to sticky it?
Or perhaps make a sticky with links to good threads like this one?

dwalstad

Betty,

Excellent question! You are welcome to pursue this. Otherwise, I and others will continue resurrecting important posts like this one.

The calcium chloride dosing procedure will probably go into the next printing of my book. I've heard several justifiable complaints that the oyster grit procedure is too slow and/or raises the pH.

Diana

fish n' chris

Greetings,

Would anyone care to offer information on a source for Calcium Chloride as described on this thread? Many thanks for your assistance.

Fish N' Chris

dennis

Aquarium Plants, Aquatic Plants, Planted Aquariums, and Aquarium Plant Fertilizer He carries all the dry chemicals useful to our hobby. The prices are very good and he is a good guy and a long standing supporter of the planted tank hobby. He carries several kinds of Ca sources, the easiest one to use is CaCl2+2H2O. CaCO3 is OK but does not dissolve easily (less than 1g per liter) CaCl2+2H2) dissolves much easier. The Cl should not hurt anything in the levels you would be introducing it.

Coincidentally, I was just figuring out a reference solution to calibrate your test kit using CaCl2+2H2O.

Step 1.
Dissolve 1.31g CaCl2+2H2O in 500ml distilled H2O
This yields a solution with 714.4mg/l Ca.
There are 7.144 mg/l Ca in 1 degree Gh
So, your solution has a value of 100 degrees

Step 2.
Dilute 10ml solution with 90ml distilled H2O.
This makes a 10% solution so its value is 10 degrees.

Step 3.

Test this dilute solution with your test kit.
If the reading is not 10 degrees, divide 10 by your reading and this is the factor your kit is off.
Example: you get 8 using the 10 reference solution.
10/8=1.25 so if you test your aquarium and get 6 degrees, you actually have 6*1.25= 7.5 degrees

DataGuru

There are several commercial products made out of CaCl.
Ice melter is one. They also sell it as a GH increaser at pool stores. Some farm stores may sell it as well.

The APC fertilator should be a good reference for how much an amount of either CaCl or Mag Sulfate will increase GH. I think if I'm reading it correctly,
1 tsp of CaCl 6H20 will increase calcium hardness by about 22ppm in 10 gallons of water.
1 tsp of MgSO4 H2O will increase magnesium hardness by about 13ppm in 10 gallons of water.

so you'd need a ratio of 2/1 calcium chloride to mag sulfate to get the 4 to 1 ratio Diana talks about earlier.

cana

Thanks. I agreed that this is the best way to get the 4 to 1 ratio.

01krisp10

Excuse my lack of knowledge on this subject, but what procedure should be used to maintain the KH along with this method of raising the GH? Or will KH additives always raise pH?

Also when you say oyster grit, are you including Florida Crushed Coral Aragonite Formula?

DataGuru

adding calcium chloride and mag sulfate only affect GH (general hardness).

Other minerals like crushed coral, crushed oystershell, aragonite, etc, dissolve over time and increase both GH (calcium and magnesium) and KH (bicarbonates). Whether you need to buffer your source water depends on the KH in the tap water. Typically abking soda (sodium bicarbonate) increases KH which increases pH. Unlike in regular tanks, I don't think KH drops over time in a NPT.

 

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