I am using ADA's Aqua Soil in my 30G. The soil used to keep my GH, and
KH down to barely detectable level, and I regularly dose CaCO3 to keep
everything happy. Now the substrate is aged, it seems that the soil is
slowly losing ability to keep the KH down, and now its back up to 3
which is about the same as my tap water. However, GH is still way low.
So my question is what should I use for supplementing Ca without
affect KH? I also dose MgSO4 regularly, but I guess using Mg alone to
make up the GH won't be a good thing, right?

Thanks a million in advance

Cheers
Kenneth

(Kenneth Ho) wrote in message . com...
I am using ADA's Aqua Soil in my 30G. The soil used to keep my GH, and
KH down to barely detectable level, and I regularly dose CaCO3 to keep
everything happy. Now the substrate is aged, it seems that the soil is
slowly losing ability to keep the KH down, and now its back up to 3
which is about the same as my tap water. However, GH is still way low.
So my question is what should I use for supplementing Ca without
affect KH? I also dose MgSO4 regularly, but I guess using Mg alone to
make up the GH won't be a good thing, right?

Thanks a million in advance

Cheers
Kenneth

ADA adds peat to their substrates already, I add peat to the onyx
sand/flourite substrates I use along with mulm from another tank.

You can use a combination of CaCl2 for Ca and MgSO4 for Mg at a ratio
of 4:1 by volume to get a good ratio of Ca:Mg.
This will not influence KH.

You can also add powdered dolomite which has CO3 for KH, Ca and Mg all
in one.
It's slow to dissolve but works.
CaCl2 dissolves almost instantly.

A KH of 3 is fine, absolutely nothing wrong with that with any fish I
know of and plants do better in harder water the same as soft water,
adding CO2 can be a problem if you let the KH get down too low below 2
degrees or so. That's bad for fish and plants.

Regards,
Tom Barr