View Full Version : Chalk Whiteboard for Calcium resources

07/08/2007, 01:09 PM
CaSO4 as main material of chalk, I used for maintaining Ca level in my tank. So far coraline alga Boosting in unbelievable.
just for alternate ca supply :)

07/08/2007, 01:25 PM
And how did you add it to your tank?

07/08/2007, 01:33 PM
I put the stick of chalk into inlet power head.
once the water turn HAZE, indicate that the Ca level is enough.
And the water become Clear in few hours.
Btw, I use biological system

07/08/2007, 01:36 PM
Have you tested your calcium levels before and after? What about pH, alk, etc... before and after? Is anything else affected?

07/08/2007, 01:55 PM
that is the interesting points.......NO other effect in parameter.
Maybe this chemical form is "INERT" in this system...........
for 2m long Aquarium, I used 5 sticks, and the level Ca will be stable 400ppm ranges in 1 month.

07/08/2007, 01:57 PM
I'm still not convinced I want to waste money on this unless I see some hard evidence of testing and readings before and after. You're not supplying any useable info here.

07/08/2007, 11:17 PM
for me the end result of using this methods.
just wanna share,...anyone have same experiences with me or not.
Im still look for the disadvantages of this method, couse its too cheap and too easy.

07/08/2007, 11:23 PM
CaSO4 is basicly gypsum/plaster...

I wouldn't use it personnally.

07/09/2007, 04:56 AM
Uh, you're still not playing along and posting before and after results as far as numbers and readings.

07/09/2007, 11:27 AM

CaSO4 is basicly gypsum/plaster...

This is not different than adding Epsom salt which is the Magnesium form counterpart, MgSO4·7H2O, which has more water than Gypsum but is part of some two-parts, such as Randy's DIY, of MgCL2 and MgSO4·7H2O


Gypsum is CaSO4·2H2O. When Gypsum is heated or looses it some of its water ---> CaSO4-H20. If it looses all of its water it forms the mineral Anhydrate. CaSO4. Side-Walk or White Board is made from Gypsum making/ giving CaCO4-H20, which is neither Gypsum or Anhydrate. But lets not knit-pick, the term Gypsum or CaSO4 is fine and close enough.

However, there is also Chalk, which is a form of limestone composed of the mineral calcite, CaCO3, not Gypsum. The chalk may break up but that dose not mean much of the CaCO3 is going into solution. Chalk is formed from by Coccolithophores. Most of it comes form England. The White Cliffs of Dover are famous for it.

This is like adding Aragamilk or Purple-Up to the tank which is or has powdered Aragonite in them, which is a wee more soluble than Calcite.

I wouldn't use it personnally.

Me either, as we do not know what its make-up is in impurities

07/09/2007, 01:04 PM
the basic of my experiment is, some kinetic reaction are involving SO4, and also some additive producer made the ingredient with base on SO4 to stabilized the microorganism in the TANK.
Just wanna share and collecting info regarding CaSO4 as the cheap Ca Stabilizer.
Is the same phenomena when i use H2CO3 instead of CO2 gas..... cheap and same result

07/09/2007, 01:25 PM
Well you don't need any more SO4 in the tank, as NSW or your salt mix has~ 2,700 ppm SO4 to begin with. If you are going to use CaSO4 it should also be sup'd with the CaCl2, so the SO4-: Cl- is in balance.