Does this look like potassium deficiency?

4622 Views 33 Replies 7 Participants Last post by YodelMogul, Mar 1, 2022

YodelMogul

Discussion Starter · Oct 7, 2021

http://imgur.com/a/FuacRI6

tank is almost a year old. Mostly heavily affected plants are wisteria and hygrophila. Possibly the little clover plant too im blanking on the name (something japan). Yellowing/brown holes forming older leaves. Things that seem okay: ludwigia, pearlweed, guppy grass, rotala hra/rotundifolia, crypts, vals.

Also, my dwarf sag just doesn’t seem to grow, getting kinda pale too. I recently increased the lighting but not sure how to quantify that. No idea what soil i used either but 1” soil + 1” gravel.
ph 8.2
currently 70 degrees but closer to 60 in winter.

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mistergreen

· #2 · Oct 7, 2021

Yeah, I would add potassium and feed more To the fishes.

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dwalstad

· #3 · Oct 7, 2021

Good advice from Mistergreen. My analysis showed that potassium can be a limiting nutrient in NPTs (my book, page 88, Table V-8). And if you change water or clean tank too much, you will remove precious K provided by the fishfood additions.

KCl (potassium chloride) is sold in grocery stores as a salt substitute. A small amount, say 1/8 to 1/4 teaspoon KCl for every 10 gal., should get your plants on their way to recovery. Dose doesn't have to be perfect.

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YodelMogul

Discussion Starter · #4 · Oct 7, 2021 (Edited)

mistergreen said:
Yeah, I would add potassium and feed more To the fishes.

Ok thank you. Im already feeding a lot. 2x a day + extra goes to the army of ramshorns and shrimps.

dwalstad said:
Good advice from Mistergreen. My analysis showed that potassium can be a limiting nutrient in NPTs (my book, page 88, Table V-8). And if you change water or clean tank too much, you will remove precious K provided by the fishfood additions.

KCl (potassium chloride) is sold in grocery stores as a salt substitute. A small amount, say 1/8 to 1/4 teaspoon KCl for every 10 gal., should get your plants on their way to recovery. Dose doesn't have to be perfect.

I’m wondering if maybe the soil i used was deficient to begin with. I dont really gravel vac and do a small (10%) water change once every month or two. I do run a filter with just filter floss…maybe thats grabbing too much stuff. How often would you suggest that I dose the KCl? Thank you!!

mistergreen

· #5 · Oct 7, 2021

You can also get potassium gluconate from the health drug section or GNC or online.

dwalstad

· #6 · Oct 8, 2021

YodelMogul said:
Ok thank you. Im already feeding a lot. 2x a day + extra goes to the army of ramshorns and shrimps.

I’m wondering if maybe the soil i used was deficient to begin with. I dont really gravel vac and do a small (10%) water change once every month or two. I do run a filter with just filter floss…maybe thats grabbing too much stuff. How often would you suggest that I dose the KCl? Thank you!!

Many soils are deficient in K.

I would add the K once and see what happens with new leaf growth. Because you don't change water that much, you might only have to add it every 2-4 weeks. You'll have to use your own judgement based on the results.

I am glad to hear that you are feeding your fish, shrimp and snails well!

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Steven F

· #7 · Oct 8, 2021 (Edited)

YodelMogul said:
Yellowing/brown holes forming older leaves.

if the new leaves are fine and only the old leaves are effected you likely have a mobile nutrient deficiency. Mobile nutrients are nutrients plants can remove from older leaves and then are used for new growth. The older leaves will then get holes and and die.

The mobile nutrients are nitrogen, Potassium, magnesium, phosphate, Chlorine (in the form of a safe chloride salt), or Molybdenum. Slow, no growth, or pale looking plants is a good indication of a nutrient deficient.

I would check your nitrate nitrite, and ammonia levels. IF all are zero a nitrogen deficiency is possible. If possible get a phosphate test kit and check your phosphate levels. Again you don't want to see a zero.

Magnesium deficiencies are very common cause of this issue. Check the GH (General harness) of your water if it is under 3 degrees harness you can try boosting GH a little with Epsom salt (magnesium sulfate)or use a Commercial CHbooster. to boost the GH by 2 degrees should be enough to prevent the problem. In fertilized tanks potassium deficiency is unlikely. Mmost fertilizers have more than enough potassium. hOwever if you are not using a fertilizer the opposite would be true. If you do decide to dose potassium try to get potassium chloride that way you could address two possible issues instead of just one.

I am not aware of any good test kits for potassium, chlorine, or molybdenum. A large water change also might help

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YodelMogul

Discussion Starter · #8 · Oct 8, 2021

Steven F said:
if the new leaves are fine and only the old leaves are effected you likely have a mobile nutrient deficiency. Mobile nutrients are nutrients plants can remove from older leaves and then are used for new growth. The older leaves will then get holes and and die.

The mobile nutrients are nitrogen, Potassium, magnesium, phosphate, Chlorine (in the form of a safe chloride salt), or Molybdenum. Slow, no growth, or pale looking plants is a good indication of a nutrient deficient.

I would check your nitrate nitrite, and ammonia levels. IF all are zero a nitrogen deficiency is possible. If possible get a phosphate test kit and check your phosphate levels. Again you don't want to see a zero.

Magnesium deficiencies are very common cause of this issue. Check the GH (General harness) of your water if it is under 3 degrees harness you can try boosting GH a little with Epsom salt (magnesium sulfate)or use a Commercial CHbooster. to boost the GH by 2 degrees should be enough to prevent the problem. In fertilized tanks potassium deficiency is unlikely. Mmost fertilizers have more than enough potassium. hOwever if you are not using a fertilizer the opposite would be true. If you do decide to dose potassium try to get potassium chloride that way you could address two possible issues instead of just one.

I am not aware of any good test kits for potassium, chlorine, or molybdenum. A large water change also might help

Water change has no noticeable effect. Yes my tank is unfertilized. I don’t have a test kit for hardness but I just know my city water is very hard. Also I have typically had a nitrogen problem (0 nitrate). Only problematic grower is that dwarf sag but it’s kind of in a darker corner so idk if that is part of the problem. For now, I’ll try Diana’s suggestion. What do you think about low nitrates though? I’ve asked myself that question in the past and decided to just leave it alone rather than to dose nitrates.

dwalstad said:
Many soils are deficient in K.

I would add the K once and see what happens with new leaf growth. Because you don't change water that much, you might only have to add it every 2-4 weeks. You'll have to use your own judgement based on the results.

I am glad to hear that you are feeding your fish, shrimp and snails well!

Okay, thank you! So cool to get advice from a legend

, I’m glad to see you active in the community that you’re passionate about and willing to help out the little guy!

janewilson

· #9 · Oct 8, 2021

In order to spot the potassium deficiency within the plants, one has to look for the symptoms of it like chlorosis between the leaf veins, curling and scorching of the leaf tips and purple spots or patches. As per my paper writer, in the case of potassium deficit plants, the fruit and seed development, root development and plant growth are all reduced at great extents.

YodelMogul

Discussion Starter · #10 · Oct 8, 2021

mistergreen said:
online.

Do they sell pure potassium gluconate or chloride? I went to the grocery last night and only found products with additives albeit food grade. Forgot to check when I went to the bulk store this am…

mistergreen

· #11 · Oct 9, 2021

YodelMogul said:
Do they sell pure potassium gluconate or chloride? I went to the grocery last night and only found products with additives albeit food grade. Forgot to check when I went to the bulk store this am…

Yes, both on Amazon.

YodelMogul

Discussion Starter · #12 · Oct 9, 2021

mistergreen said:
Yes, both on Amazon.

Hand Fluid Finger Thumb Drink

found it! Code name nusalt

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mistergreen

· #13 · Oct 9, 2021

good find.

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johnwesley0

· #14 · Oct 9, 2021

mistergreen said:
good find.

Should I pulverize the pill or should I just drop the whole thing in?

Liquid Fluid Ingredient Paint Bottle cap

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mistergreen

· #15 · Oct 9, 2021

I would think pulverizing it would do. I have the powder form.

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YodelMogul

Discussion Starter · #16 · Oct 10, 2021

mistergreen said:
I would think pulverizing it would do. I have the powder form.

I’m curious do you know, with KCl, what happens to the chlorine? Does it become toxic in the water or does it simply evaporate off?

mistergreen

· #17 · Oct 10, 2021

Plants do use some chlorine but too much would be toxic. Not sure on how much is too much. Tap water has 2-4ppm of chlorine and that generally safe but that’s usually some complex chlorine molecule, not Chlorine ion.

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YodelMogul

Discussion Starter · #18 · Oct 10, 2021

mistergreen said:
Plants do use some chlorine but too much would be toxic. Not sure on how much is too much. Tap water has 2-4ppm of chlorine and that generally safe but that’s usually some complex chlorine molecule, not Chlorine ion.

one more question 😁 a different tank but a species I’ve always had trouble with. My AR keeps melting, here you can see the leaves disintegrating as well as the base of the stem. Would you say this might be nitrogen issue? Also some other plants may look like they’re producing small leaves but I don’t know if they’re getting enough light.

Flower Plant Organism Terrestrial plant Petal

currently I don’t feed this tank other than an algae wafer maybe one every day or two so nothing from fish food. Also lots of floaters and a pothos going crazy…wondering if they’re sucking too much nitrate. Typically my test doesn’t show any, is that a good indicator or nitrogen deficiency?

thanks for all the help mister green, you rock!

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mistergreen

· #19 · Oct 10, 2021

Thanks.
CO2 and light seem to make AR grow.

dwalstad

· #20 · Oct 11, 2021 (Edited)

I’m curious do you know, with KCl, what happens to the chlorine? Does it become toxic in the water or does it simply evaporate off?

The Cl- (chloride ion) from KCl is absolutely harmless at normal concentrations. It is the chloride of ordinary table salt (NaCl) and seawater. Virtually, all freshwaters contain some chloride. Most aquatic plants will tolerate salt concentrations (NaCl) below 0.1% or 1,000 ppm. Above 1,000 ppm NaCl, you'll get reduced plant growth. I don't have data on KCl inhibition of plants, but I would try to keep dosage as low as possible--enough to reduce the hole-in-the-leaf symptoms you describe.

I try, but not always succeed, to calculate a KCl dosages on the order of 10 ppm. If you add KCl forever and never do a water change, yes it will build up to levels where the K+ (potassium ion) might inhibit plants. (The Cl- ion would probably be less problematic than the K+.)

Bottom Line for those that did not take a high school chemistry class: Chloride (Cl-) stays in the water and is harmless. In contrast, chlorine (Cl2) is a highly toxic gas used in waste water treatment to kill bacteria. It will degas off rapidly (usually within a day).

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