Is possible from my understanding that GH reading can mean that there is more clacium than magnesium or more magnesium than calcium. |
Reading will be the same but perhaps more of one than the other.
True. Hardness is determined by any one of several minerals, calcium and magnesium being the two most prevalent in "hard" water but a few others can impact the GH too. While I was experimenting with raising hardness, I did so in one tank solely with magnesium, in the form of magnesium sulfate (pure Epsom Salt) and this alone raised the GH from zero to 4 or 5 dGH. But that caused other difficulties with the plants, so I stopped. Calcium is the crucial mineral for invertebrates and plants. More on this in the response below.
Do you no longer use dolomite or coral in your tank's? I find it interesting that the snails do well for you with soft water and fair poorly for me without steps to provide some form of calcium. |
I see a little calcium in flourish comprehensive but always assumed that plant's utilized this amount fairly quickly.
I used to use dolomite in my larger tanks, and nothing in the smaller. Back in the 1990's pond snails did poorly, multiplying very minimally. I had no Malaysian Livebearing back then, no stores locally had them. My dolomite ran out; that in the filters gave out after 10+ years, and I couldn't find any locally. That was when I tried the magnesium experiment in one tank, and Seachem's Equilibrium in another. The excess of magnesium with insufficient calcium and potassium caused the swords to melt so I ended that experiment. The Equilibrium seemed expensive long-term, so I ended that test and went to aragonite. This is supposedly very similar to dolomite, containing mainly calcium and magnesium. I am using CarribSea's crushed coral with aragonite gravel. I figured this would provide calcium and some magnesium.
I should explain why I did all this before continuing. The fish are fine, I have wild-caught soft water fish so no issues there. But the plants were clearly showing something. After research, it turned out that I have a calcium deficiency, and with Echinodorus this causes the plants to take up more iron, resulting in an iron excess which slowly kills the plant. My large swords in both tanks literally collapsed into mush due to the iron. I also noticed holes in the leaves of swords in other tanks, and then in the pygmy chain swords in the 70g which has Flourite substrate and receives weekly dose of Flourish Comprehensive. Clearly the calcium, magnesium and potassium in Flourish is not sufficient in my situation.
Back to the experiment. The aragonite in the 115g and 90g blew the pH up to 7.2 and 7.4 when it had been at 6 (or lower). This over a couple days, and with only a cup of aragonite in the filter. I removed half the aragonite. The GH has been around 3 (from zero) and the pH, after 3 months of this, is now around 6.6 in the 115g and 6.8 to 7.0 in the 90g. I don't mind this pH is these two tanks, but it is not acceptable in the smaller tanks which have more delicate wild fish, so this obviously isn't the solution. And the GH at 3 dGH is still not enough for the calcium needs of the plants. They are better, during the last 3 months, but not yet "normal."
I decided to go with Equilibrium, which is about the only product I can find that deals with this issue. Seachem do have a new line of planted tank products out, called Aqua Vitro, but only in selected stores (cannot buy from them or online) and no one here has it yet. It may be better when available.
I left the aragonite in the two tanks and started using Equilibrium. Now after about a month, the GH in the 115g and 90g is stable at 6 dGH, the pH has remained at 6.6 and 6.8 respectively (which is fine for those fish), and I have noticed already a real improvement in the Echinodorus and the chain swords. Equilibrium contains calcium, magnesium, potassium, manganese and iron. I am still dosing once weekly with Flourish Comp. These two tanks seem stable.
The 70g with Flourite substrate was also having these plant issues, so I am using Equilibrium in this tank too, without the aragonite since I do not want the pH above 6. GH is now 5 dGH which is fine. I am still seeing some holes in the swords, though less than before, so i will continue to monitor. I may have to up the potassium in this tank.
I am also using Equilibrium in the 33g and 20g now. GH is 5 dGH with pH still below 6. This again is ideal.
I do not like using products if I can avoid it, but I had no other options. And, Equilibrium is not chemical, it is pure mineral salts: potassium sulfate, calcium sulfate, magnesium sulfate, ferric sulfate, manganese sulfate. It is expensive, but less so in bulk (I got the 2.8 kg tub, this should last several months).