What is causing necrosis in my plants?

[LabTest57]

Well, so far it seems that regardless of hard or soft water or high or low nutrient levels (in general) aquatic plants may not flourish if algae is competing for the nutrients and if the water temperature is above 80 degrees fahrenheit. From countless experiments, I found out that stunted growth is mostly due to not having a minimum amount or almost no water-soluble nutrients in the water, having brown, BBA, or hair algae (plants can flourish with cyano.), and if the water temperature (unless it's high tolerant tropical plant) is above 80 degrees Fahrenheit.

There's only two things to consider for aquatic plants to flourish: One is the intial conditioning and/or transplanting. Second is keeping up with the needs for flourishing plants.

To keep them alive you don't need them to flourish, however, having a bunch of fast growing and lush aquatic plants is a great scene for any aquarium.

Since most plants are grown emersed and then shipped to LFS's and become submersed, there's the risk of the plant either dying or regrow (leaves die or whole plant temp. seems to die) with duller leaves and stems.


One of my test tanks have a lot of submersed amazon sword plants--- growing dull leaves with short stems; however, the general water-soluble nutrient levels (e.g. most common macros and micros) is at a minimum at levels lower that what can be achieved with Seachems' Comprehensive Flourish (aquarium plant fertilizer) product. Lighting is very low, but the water temperature is at 65 degrees fahrenheit and very little algae is present (mostly cyano).

In a same experimental tank with the same setup (Note: these are hard-water aquariums that are about 100 gallons in volume) I have Black Beard Algae (BBA) instead, but the plants are dying. It's been this way for at least a month. As of last week, I've been scarping off BBA from all over the tank, and have cut the nutrients available in the tank to almost nothing (no more water changes either). Right now the BBA is completely gone is hasn't returned, yet. For no known reason, most of the amazon plants have started to sprout new leaves with perfect structure and coloring (very-green).


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So, to the best of my knowledge, I believe one must setup the right environment and conditons for their plant to survive. After, if their plant is flourishing (slightly), one can use fertilizers, better lighting, and CO2 to keep the plants healthy and to keep flourish; logically, this should keep most of the plants from having stunted growth or necrosis. Although, one should only proceed to the next step if they really can keep up with a stable dosing regime (either with fertilizers, CO2, or both).


Still, until I finish my last experiments after January, I will have to wait for any new results to prove if this solution/method is right.

[Tech Support AN]

Thanks for the update! We look forward to hearing the end results of your experiment!

[LabTest57]

Well, I wouldn't overdose on potassium. I found out that green algae can proliferate in a solution with high Potash concentration. Actually, it's in my test tanks that i've noticed this regardless of water temp. and general water-soluble nutrients, however, to jumpstart the bloom one needs to have at least 1 ppb of phosphate/phosphorous in the solution for a few days.

My amazon swords and even crypts are doing very well in high phosphate-concentrated water without the recommended Potash and micronutrient (water-soluble) concentration levels.

I do keep magnesium, calcium, and carbon or CO2 levels in check, however, to jumpstart the "new-submersed-growth" process for bought amazon sword plants from my LFS I had to dose the recommended macro and micro nutrients for at least 2 months. Amazon vegetation have a unique way of shedding and changing leaf + stem form from season to season or just wet to dry season and vice versa.

I also figured out that bicarbonates (e.g. sodium bicarbonate), and the buffered PO4 from Neutral Regulator are both neccessary, because tap water can contain buffers that buffer water at or above a pH of 8 and water changes and/or algae/plants can reduce the effectiveness of the buffered PO4 (less buffering capacity). This is why it's better to keep bicarbonates as a back-up buffering system for freshwater, because the water will be in the 7.0 to 7.8 range. A more narrow range will depend on the capacity of each buffer in the solution. High nitrates like around 40 ppm and above can affect pH by causing it to decrease because of nitric acid (i.e it acts like a temporary acid-buffer).


One of my 70 gallon tank containing fish and plants use Neutral Regulator at about 3 ppb of PO4 and bicarbonate alkalinity of ~40 ppm, carbonate alaklinity of ~15 ppm, nitric acid concentration at 20 ppm. The bio-load is very high from over 50 two inch goldfish. Nitrates are kept at a minimum from a coil-denitrification filter (hard to maintain though). However, the point here is that I haven't added any buffers, bases, acids, or made any water changes in the past month and a half; my pH is constantly at 7.0 and my alkalinty only drops 5 ppm every 2 weeks.


My plants consist of crypts only. They are doing very-well in the low water-soluble nutrient environment, however, a CO2 custom-made pump (yeast+sugar+water+bottle+valves and airline tubing) together with the high PO4 concentration had allowed them to flourish in a different way as leaf and stem formation aren't as colorful (lack of proper structure), but growth is consistent and necrosis isn't a problem nor any yellowing issues as well.

Yes, CO2 is a good thing for lack of lighting and nutrients, and PO4 as an emergency nutrient for survival or for quick blooming. With regards to algae blooms, this is avoidable with low nitrates, and enough flourishing plants to compete for water-soluble nutrients. If not, nutrient tabs for plant roots or adding enough/recommended macro and micro nutrient concentrations for flourishing plants (if and only if your plants are flourishing and growth is high) can prevent algae blooms and damage to plants from algae blooms (i.e. nutrient deficiencies resulting from nutrient competition between algae and plant). To get rid of green algae can take a few weeks, and a few months for brown algae. Cyano. or blue algae doesn't really cause any competition problems, however, it's Black Beard Algae that one may get confused for, which is (in my opinion) the number one "bad" algae in any freshwater tank.

[LabTest57]

[QUOTE=LabTest57;7507] High nitrates like around 40 ppm and above can affect pH by causing it to decrease because of nitric acid (i.e it acts like a temporary acid-buffer).[/QUOTE]

Ooops, my mistake. Thinking of nitric acid formation. Actually, nitrates as the conjugate base of nitric acid (as this acid reacts with carbonate salts,etc. to form alkaline nitrate salts...), nitrates are entirely alkaline. The nitric acid temporarily lowers the pH if there's enough alkalinity buffering (if not, the difference will be greater and last longer) in the water, however, nitrates will keep the pH slightly alkaline. I guess less nitrates = less alkaline buffering capacity in total of all buffers together. The rate of nitric acid formation compared to nitrate concentration in the water, just makes different temporary and slight fluctuations.

[LabTest57]

I've decidied to drop this topic as well. The experts always know what they're doing. I for one agree, but find it hard when there's so much misinformation on the net.