KH and GH recommendations for Aquatic Plants

[Julie]

Just wondering what the recommended average water hardness is for aquatic plants?

thanks.

[artw]

in order to prevent PH crashes I try to keep the KH around 4.   I add 1/2 tsp of baking soda every so often with my fertilizer to accomplish this.   I also try to maintain my GH around 4 to provide some hardness (mg and ca etc) for the plants,  I accomplish this by adding Seachem Equilibrium after the weekly waterchange.

[Julie]

Do you have C02?

My problem is my water is too hard, it's around 15.

[artw]

yes.

[Julie]

What is your PH and GH before C02?

[artw]

2 and 2

[Julie]

Is this right out of your tap?  Do you have any for sale?
Do you know of any members with hard well water and c02?

[Underwater]

PH 2?

Do you wear goggles and gloves when handling your tap water? or did you mean your GH and KH is 2 and 2?

[artw]

yes my GH and KH is 2 and 2.  the PH comes out high but it levels off around neutral.

Julie do you want to come to ottawa and get some tap water from me?  pretty much everyone on the ottawa city water system has a KH and GH of 2 in their taps.

[Julie]

Thanks Art...but it wouldn't work over the long term.
I'm thinking c02, I'm having some brain flatulence this morning wanting to convert my barebottom 55 Discus to planted.
I just wonder though because of the buffering capabilities of my water, would c02 work?  PH down does nothing.

[Underwater]

CO2 will bring down the KH and PH, but will not reduce the amount of dissolved solids. [edited] Only add co2 if you have enough plants with good lighting to absorb it all.

You could always add R/O water to soften it, but it's expensive. I'd just try plants in the hard water. Pick hardier species, and you should be fine.

Since you're planting your tank, you should have Co2 if your lights are over 2 WPG*

*rule of thumb

[BigDaddy]

CO2 does not displace oxygen from the water.

[Julie]

Hey BD - does ragweed pollen disperse 02 from lungs?

Anyways I tried the high lighting in that tank and the plants lived for a bit but that was it.

[BigDaddy]

In higher kH settings, CO2 will still bring down the pH (only pH not kH).  However, it will take more CO2 to cause a shift in pH.

For example, and using numbers I'm taking out of the air

It might take 1 cubic foot of CO2 to drop the pH from 7 to 6 in a tank with a kH of 3

In a tank with a kH of 15, it might take 4 cubic feet of CO2 to get the same drop to a pH of 6 from 7


So, the moral of the story is, the lower your kH, the less often you have to refill your CO2 canister

[Underwater]

CO2 does not displace oxygen from the water.

After looking around a little bit, I realized you're probably right.

[gonzobluefuzz]

I think this is a graphical version of whats posted one or 2 up

it's down the bottom  http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

HTH

cheerz

[Julie]

According to chuckieboys calc my c02 is at 4.5ppm after degassing.
He explains  ( in just a few hours, that excess CO2 will dissipate from the water, leaving the normal 3-4ppm, and the pH will rise.)