Intreasting info but i think your missing the point a bit on why i or other people go to dirtied tanks. I started exploring this method because i didnt want to drop a couple hundred on a co2 setup. People add dirt to tanks in order to create and explore a more natural ecosystem within their tanks, which is what i want. Dianas book is a absolute monster to get through but is very imformative for anyone who actually wants to learn the why and how behind the functions and ecology of a at home aquarium. I dont want to have to micro manage my aquariums because i essentially cut out the the natural functions in favor of added mechanics. Its not to say that i at some point wont try a full co2 setup with the ferts etc, but right now i dont have the space or ability to affored all those addatives.People add soil to the tank simply to add nutrients the plants need. However you are adding fertilizer. The fertilizer should take care of nutrients unless there is a problem We all would like to assume that all fertilizers on the market will provide all the nutrients plants need. Unfortunately the reality is the most don't
For EI dosing Everyone doses NPK for macros Unfortunately NPK are not the only macros. The full list of macros is N, K, Ca, MG, P, S, Most people don't worry about calcium and magneisum and sulfur simply because most of the time tap water it. But that isn't always the case. And if you are using RO water your tank would definitely be deficient in these.
You should monitor your GH level with a GH test kit. The GH test detects only calcium and magnesium. So it could tell you if you have ea lot or very little. But note it doesn't tell you if your water has only calcium or only magnesium. If possible look up your water utility water quality report. It might list the typical values for Ca and Mg in your water.Or you could get a GH booster from the store and boost your GH to see if it helps. Seachem Equilibrium has Ca, Mg, and S and would satisfy that need. Or you can make your own.
For the EI micros most people use CSM+B. Everyone assumes it takes care of all of the macro needs but again it has some of problems:
For most successful EI tanks enough CO2 is added to keep the PH in the low 6 to 6.5 range. which does help prevent iron loss. But the easier solution is to use a form of iron that is stable at your water PH. One of the best iron nutrients for aquariums is Iron DTPA. It is stable at a ph of 7.5 or less but may be usable up to about 8. Iron gluconate is easy to find (Seachem iron uses it) and PH has no effect on it. but it is best used in frequent small doses because bacteria will consume the gluconate and destroy it. The last choice is iron EDHHA with is stable at a PH of about 10 or less. However this for of iron does color the water red. so it is best used in small amounts when the color might not be noticeable. At a dose of 0.03ppm the color might not be noticalble.
- The big issue is that the iron nutrient in it is Iron EDTA. Iron EDTA is only stable at a PH of 6.5 or less. Ifyour PH is above that level the iron will convert to iron oxide which is unusable by plants.
- It doesn't contain enough zinc to satisfy the needs of the plants.
- And you are using RO water it doesn't have chlorine. Yes Chlorine is a nutrient but plants can't use it in it's toxic and corrosive gas form. Plants typically get it from safe chloride salts such as calcium chloride, potassium chloride, sodium chloride, or magnesium chloride. Tap water is typically sterilized with chlorine. And even after using a water conditioner the chlorine is still pressent in the form of chloride salts the plants can use.
GLA now sells a upgraded CSM+B iron mix that now does incorporate iron DTPA and additional zinc.IF you are using tapster you shouldn't have to worry about Chlorine as long as you do weekly water changes.
As to liquid carbon I never saw anything indicating it helped my plants and in fact it is toxic to some. If you have a paint ball tank You could use the inverted bottle methode to get CO2 into your water. This video shows it. It is much more efficient at getting CO2 into the water and you cannot put too much into your tank which can kill fish. Note drop checkers don't work at the low CO2 level this methode provides in the tank. But dispite that my plant still do pearl slowly.
Also note I only dose macros and micros once a week right after a 50% water change in my 5 gallon srimp tank. i think the the every other day recommendation for micro dosing was done due torn losses and the low level is zinc in regular EI micro mixes. Also I don't use bright light.
If any of the issues I have mentioned apply to your tank mixing them should help your plants without the need of adding soil to your tank.