[MacFan]

I've been using Barr's GH Booster and nothing I do (stirring with a whisk, dissolving in boiling water, etc) seems to get me around the tank looking like a snow storm just hit after adding it. While it mostly dissipates after 12 hrs or so, I would still like to avoid it if possible.

I did some research and found that GH Booster consists of:
3 parts Potassium Sulfate
3 parts Calcium Sulfate
1 Magnesium Sulfate (Epsom Salts)

Apparently it's the Calcium Sulfate that is difficult to dissolve.

I was reading Rex's Planted tank guide and learned that Calcium Carbonate would add both GH and KH in equal amounts, but it too is difficult to dissolve.

Rex goes on to recommend using Calcium Chloride and Epsom Salts to boost GH and Baking Soda to boost KH. He notes that you need to add these separately or you will end up with Calcium Sulfate which is hard to dissolve.

The main difference between the GH booster and what Rex is recommending is Potassium Sulfate. While some descriptions of EI include dosing PS, I read that there is plenty of Potassium in the Potassium Nitrate.

My question is, does the Potassium dosing in EI assume that Potassium exists as part of the GH (whether added or existing in the water)? If I stick with the GH Booster formula, can I make it with Calcium Chloride instead of CS as long as I use it in a proportion that provides an equivalent amount of calcium? AquariumFertilizer.com sells both CC and CS.

Incidentally, my LFS said they reconstitute RO water for their tanks using a marine buffer product, but I'm looking for a solution that uses raw ingredients which come at a lower cost than commercial products.

Michael

 

[MacFan]

Why not mix up a gallon jug of solution so it can have time to dissolve before you do a water change?

The GH Booster also has ferric sulfate and manganese sulfate as well.

Well, it used to have 5 components as it duplicated a commercially available product. But at some point it changed to the formula I mentioned (that's what is on the label, and has been confirmed elsewhere.)

 

[MacFan]

If you use only Calcium Chloride (CaCl2) to add calcium you add too much Cl- and your plants may be not very happy.
(snip)
To raise the KH value you can use Baking Soda (NaHCO3) but in this way you are adding a lot of sodium (Na+). Personally I use a mix of NaHCO3 and KHCO3.

According to The Barr Report July 2006 newsletter, Chloride is not the same as Chlorine: "Chloride is an essential nutrient for plant growth and metabolism." and "Although the amount of chloride required by plants for photosynthesis is met by extremely small concentrations, high rates of chloride have notably positive effects on soil/root relations, such as inhibiting the conversion of nitrate to ammonia, enhancing manganese availability, and increasing beneficial microorganisms."

The article also addresses sodium: "Generally, sodium is not considered a limiting factor for freshwater plants, unless sodium concentrations reach upper levels where freshwater plants cannot survive. Plants that are salt tolerant, and Na tolerant tend to have very good gate keeping in their roots and leaves, this process keeps the salt out, and the freshwater in."

Since we do regular water changes under EI, the chances of reading bad levels of sodium is minimal. Having seen the amount of salt it takes to produce sea water (1/2 cup per gallon), the sodium contained in the baking soda required to get to 4 dkh (something like 3/4 tsp per 20g) comes nowhere close.

That said, there must be a reason GH booster uses Calcium Sulfate rather than Calcium Chloride. The reason might be because they wanted a single component and mixing Calcium Chloride and Epsom Salts directly would result in Calcium Sulfate anyway. So is this a matter of convenience or is there more to it? According to the fertilizer calculators, the amount of calcium for a portion is very similar between the two. Since EI over doses and uses water changes to keep levels in check, it doesn't seem like there should be a problem.

Michael

 

[MacFan]

Yes, but my point is that we're far from creating sea water with the sodium contained in baking soda. The chart on this page (http://www.finostrom.com.gr/images/aqua/fertilizers/map.htm) lists Na as a beneficial nutrient for aquatic plants.

 

[MacFan]

I agree, but I'm not adding sodium to my tank. (Besides, sodium alone is unstable and would explode upon contact with water!) I'm adding Baking Soda which is the standard recommendation by all, including plant pro Tom Barr. The commercial product Wardley's Raise pH is literally baking soda (http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=8007016).

But I wasn't asking about baking soda. I was asking about Calcium Chloride.

 

[MacFan]

That is true of most things. We would be dead without oxygen, but pure oxygen would be toxic to us. The target range for iron in planted tanks is 0.2-1.0 ppm.

Learning the necessary components and the appropriate dosage levels for our needs is a function of research and experience. Thus my posting here to ask questions I have as a result of the research I have done.