Sorry for delay getting back. Life happens, didnít have time set down and write a clear answer.
You might have been overdosing, but yes with their dosing philosophy your adding to much at water change and then none midweek. This is what I call feast or famine dosing you dose a little bit to much at 1st of week, algae comes forward because it is in excess, then about day 5 some of the micro nutrients run out, when that happens plant growth stalls and again algae has the advantage, itís a rollercoaster ride with of nutrients for your plants. In a Euro dosing scheme you want a flatter level of nutrients through the week, never in excess, never in complete depletion.
The JBL product line and dosing instructions are very confusing to me. Sounds like you should dose for change water and then dose again midweek. The 24drops are for every day dosing of quickly depleted micro elements that you dose in between the other fert. They will not add Mg or P. Did you get a phosphate test? Salifert is best one IMHO.
With as hard as your water is not sure you have a Mg problem. See if your city has a water report that might give a clue as to Mg/Ca ratios that all that hardness is made of. If you want dose Mg just buy some pure Epsom salt, no fragrances, itís magnesium sulfate. All it adds is proper ratios of Mg and sulfur to water.
Now getting into ratios Iíll introduce you to mulder chart. For proper plant development all these elements are needed, in proper ratios. I forget how many decades this chart has been around.
None of JBL fert have any nitrate, phosphate, Ca or Mg listed on this chart, they depend on that coming from your change water (Ca/Mg) or from fish feeding (N/P), sometimes your city water might have some nitrate and/or phosphate. You can easily test your tap water for those if you got the tests, Ca/Mg ratios is a little harder. Again your city water report might tell you everything you need to know. Set a glass beer mug full of tap out in open air for 24hr to absorb/expel gases then measure PH, GH, KH, Nitrate and Phosphate. That is true reading of water you have to work with. Any deviation beyond that reading is happening because environmental factors in tank (over feeding, wood or rocks dissolving).
Getting back to Mulder chart above. Go to Calcium at top, then follow the green pointers away from it. What that is telling you is that high levels of Ca in water (which might be a very real factor for your tank) actually interfere with the uptake/absorption of the other elements that it points to. You increase Mg to counteract that, now follow dashed black line between Mg and Phosphate, thatís telling you that Mg and P have a codependent relationship, bring Mg up you may need increase P levels with it for proper ratios.
Note that the Mg and phosphate deficiency I mentioned earlier are both on the end of green pointer coming away from Ca, going by appearance only with no real phosphate test reading to back it up Iíll go with your Ca to Mg and/or P ratios are out of wack.
First off an apology to @DaveKS
- I'm sorry for my impatience last time. I need to remember that we're all enthusiasts here, helping each other out of a love for our hobby, when our busy lives allow.
Secondly a thank you again to @DaveKS
for the detailed, informative and highly educational response, in the last post - very much appreciated.
Although I have 5 years under my belt in fishkeeping, I'm a relative novice in the science behind successful plant keeping. I've since bought an API Phosphate test and a Salifert Nitrate test. The full range of readings, following Dave's guidance were as follows:
Water Testing Results
Test Tap Tank
GH 22į 22į
KH 14į 14į
PH 8.0 8.2
Nitrate 50 ppm 50 ppm
Phosphate 2 ppm 5 ppm
I also researched the local water board water quality report for last year. From this report, I pulled out some of the key parameters as follows:
Calcium* mg/l 126
Magnesium mg/l 3.86
Boron mg/l <0.09
Copper mg/l 0.026
Iron mg/l <7
Manganese Ķg/l <1
Sulphate mg/l 88.2
Sodium mg/l 12.9
*Total hardness as Calcium - 132.1 mg/l
Nitrate mg/l 35.1
Phosphorus mg/l 0.866
Potassium mg/l 2.72
Attempting to follow what Dave has tried to teach me, my thoughts/observations are:
> Calcium content of the water supply does indeed appear to be high.
> The magnesium content of the water supply seems minimal in comparison. This appears to corroborate the diagnosis of the plants be deficient in this nutrient. BUT..
> Of those tap water elements tested only phosphate(phosphorus) is being affected by the tank environment, building up substantially it appears. This is confusing me, as if phosphorus and magnesium are co-dependant, wouldn't this mean that there are correspondingly high levels of magnesium in the tank?
Other questions/doubts in my mind:
> Nitrate (Nitrogen) levels in the tap water are high. I use Tetra Nitrate Minus to manage levels in the tank, for the fishes benefit. But I notice that this is said to reduce NO3. Could this be limiting the availability of this nutrient to the plants, causing a nitrogen deficiency? Or does the tank water reading of 50 ppm disprove this?
> I see from the Mulder chart that Calcium can also suppress Potassium. I don't currently add this nutrient. On line images of leaves with a Potassium deficiency look similar to the issue I'm dealing with.
>I see that the JBL Pro Flora micronutrients complex is stable only at PH 4-5. Where I have 8.0-8.2, does this mean that it is breaking up and losing potency?
I have since swapped to Seachem Flourish, which doesn't appear to have this issue. It has all of the elements that the JBL product has, plus magnesium and other elements.
Should I now look for a fert that doses all of the 3 macronutrients NPK - Any recommendations? (I have shrimp, khuli & catfish in my stock so whatever I add, it has to be safe for them).
I'll check back here in a week or so. Any additional thoughts and advice would be much appreciated.