Hi all,
I haven't noticed any algae growth.
Possibly not iron then, because algae take in nutrients directly through their cell walls, and they should show a quicker response to available iron.
This maybe a silly question but can you have to high a nitrate level? As mine are about 80ppm. Could that inhibit the uptake of other nutrients?
It could, but that is unlikely to be an issue with the Frogbit. Uptake issues would only affect another monovalent anion (like Cl-), and very few of those are essential plant nutrients.
Both the lack of growth and high NO3 level may relate to <"
Liebig's law of the minimum">. Plant growth is nutrient dependent in the same way that cars are built on an assembly line, at the speed of the limiting nutrient (or the limiting operation in car assembly). If one nutrient, or car component, is missing then the whole process grinds to a halt.
Please correct me if I am wrong, from my understanding as my frogbit has very little root growth that would I indictate sufficient nutrient levels.
Plants are quite plastic in how they allocate resources, so often high nutrient conditions they allocate less biomass to roots, because a small root area is garnering all the nutrients they need,
but, you could also get restricted root growth where the plants are struggling to grow new tissue.
Maybe it would be worth doing a full water test to measure what amount of nutrients are in there.
It would be very useful, but it is quite problematic.
A proper water testing lab. could do it, but you are talking about a lot of money, because it is going to take several hours of a scientists time and several hundred thousand £ of analytical kit. Marine aquarists are having their water tested <"
via ICP">.
Do you have a TDS (conductivity) meter?
cheers Darrel