View Full Version : soft as a baby's bottom

10-10-2006, 06:34 PM
I am in central North Carolina and the water is so soft here I can not keep the ph high enough for my african rift lake tanks.
I keep the big three Tanganyikan, Malawi, and Victorian (including satilite lakes). I have reasearched via the internet and wanted to get some thoughts from the members here.

I purchased pulverized limestone at home depot to add to my holding tank where I will pretreat the water for hardness and ph.
I pretreat as the water comes out of the tap at 8.2 ph and in two weeks drops to below 6.0. Needless to say my fish will not breed with that kind of stress.

I have not taken hardness tests yet but at this point who cares. if it is dropping below 6.0 after a healthy dose of seachem tankanyikan buffer, I know it is too soft. What are your experiences with limestone additives for hardening water? Do you have any other ideas to harden water. I appreciate you input.

10-10-2006, 06:52 PM
Dolomite > aragonite > crushed coral/limestone

Due to a better ability to disolve.
I would say if it is not buffering yet, add more until it does.

I have a running experiment with one quart of RO water and a cup of aragonite. After day one with no circulation I saw:
pH: 8.0
GH: 50 ppm
KH: 100ppm

I'll update with new numbers since it has been a week.

10-10-2006, 06:56 PM
I think you need to buffer your tank and that should prevent those huge swings. A media bag of crush coral (aragonite) in your filter will add (leach) hardness to your tankwater. You can also use a buffering substrate such as aragonite, or better yet magnesium calcite. You can also use rocks of limestone, dolomite, etc....

You will still need to doctor water for changes and such, but you should stabilize at least around 8.0 ph and have acceptable hardness.

Check here for a lot of technicale info and a cheap recipe for buffers.

Steve C
10-10-2006, 08:45 PM
I think the Carib Sea cichlid mix gravel and sand would help as well...but it would be a bit of a project to switch.

10-10-2006, 10:03 PM
I know I heard somewhere that it's 3 pounds of crushed coral for every gallon. That would be for a substrate.

Update: Just prior to dumping it all into my cannister.
pH: 8.0
GH: 100
KH: 150

That's 1 cup (~8 fluid oz) to a quart of RO water with no water movement for a week.

10-10-2006, 10:53 PM
So from what I am hearing I should use limestone or crushed coral to increase my Kh. I should use salts to increase my Gh.
By the way I will be adjusting water for over 40 tanks so I seem to be leaning towards the pulverized limestone that I can pick up for $3 dollers per 40 lbs.

I did some tests tonight:
Gh 2 degrees
Kh 6 degrees
ph 7.4

If I am understanding correctly the limestone will increase the Kh
and some marine salt will increase the Gh. I will also look into baking soda to help the Kh.

Thanks for the imput. If I have not understood, please straighten me out. I have too many fish to misunderstand a small detail and kill a whole fish room.

10-11-2006, 04:27 AM
I think its important that you add buffer material to your tank(s) at minimum the media bad of aragonite in a filter is cheapest. Without an in-tank buffer you may continue to have PH swings.

If your adjusting that much water then I suppose the pulverized limestone would be cheapest.