# Does this look like potassium deficiency?



## YodelMogul (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 (Mar 3, 2007)

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


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## dwalstad (Apr 14, 2006)

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 (Oct 7, 2021)

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!!


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## mistergreen (Mar 3, 2007)

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


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## dwalstad (Apr 14, 2006)

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 (Aug 1, 2021)

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 (Oct 7, 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.
> 
> ...


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!


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## janewilson (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.


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## YodelMogul (Oct 7, 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…


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## mistergreen (Mar 3, 2007)

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.


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## YodelMogul (Oct 7, 2021)

mistergreen said:


> Yes, both on Amazon.











found it! Code name nusalt


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## mistergreen (Mar 3, 2007)

good find.


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## johnwesley0 (Feb 23, 2021)

mistergreen said:


> good find.


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


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## mistergreen (Mar 3, 2007)

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


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## YodelMogul (Oct 7, 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?


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## mistergreen (Mar 3, 2007)

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 (Oct 7, 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.








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 (Mar 3, 2007)

Thanks. 
CO2 and light seem to make AR grow.


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## dwalstad (Apr 14, 2006)

_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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## Steven F (Aug 1, 2021)

YodelMogul said:


> 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.


Sorry for the late reply. zero ammonia, nitrite and nitrate is not good. All zeros mean you plants are consuming all the nitrogen in the water So theirmaight not be enough to satisfy the plants. And if nitrogen is insufficient plant will not consume any other nutrients which could build up to toxic levels. I would recommend you always have a small amount of measurable nitrate in the water. 

After I first setup my tank I had no plant growth. I din't understand it. I saw a phosphate test kit at the store and bought it hopping it would provide a clue. when i ran the test it was offf scale high (over 30ppm). I eventually figured out is was nitrogen and added nitrogen to the tank. Phosphate then started to drop and my plants started to grow.


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## johnwesley0 (Feb 23, 2021)

Steven F said:


> I eventually figured out is was nitrogen and added nitrogen to the tank. Phosphate then started to drop and my plants started to grow.


Or, you could just feed your fish more often. Isn't "nitrogen" just a fancy word for fish poop?


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## YodelMogul (Oct 7, 2021)

mistergreen said:


> Thanks.
> CO2 and light seem to make AR grow.


per my original K deficiency I ended up dosing 6.75 g of potassium sulphate in my 40 gallon 1x weekly for the past 4 weeks or so. I was aiming to achieve roughly 20 ppm K. My plants all look fantastic except for the K hog hygrophila that was my original concern. While it does look to have improved it still seems to be suffering. As I cannot test for K I am wondering if it is safe to assume that at this dose weekly without regular water changes will I avoid potassium overdose? I may just remove the hygro but I am quite fond of it. I’ll have to check the symptoms again but the only thing I have noticed is deformed very twisted new growth on a few leaves of valisneria which doesn’t concern me at all. Please advise ?


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## mistergreen (Mar 3, 2007)

New leaves look good. Prune off the old affected leaves.


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## dwalstad (Apr 14, 2006)

Be very careful adding that much potassium sulfate (K2SO4). Bacteria in the soil convert sulfates to toxic H2S, which can kill plant roots. Use KCl (potassium chloride) sold in grocery stores as a "salt substitute. And you don't need 20 ppm K. That high level is probably for high-tech tanks with CO2 injection and very rapid plant growth.

That said, the added K didn't solve your "holes in the leaves" problem, so I would either stop or reduce the K dosing.

Stem plants don't do that well in Walstad tanks. If your only problem is a few dead Hygrophila leaves, I would consider your tank a success.

Nice tank!


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## mistergreen (Mar 3, 2007)

You can get Potassium gluconate as well in the health drug section.


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## johnwesley0 (Feb 23, 2021)

mistergreen said:


> You can get Potassium gluconate as well in the health drug section.


I can vouch for that. The tablet form made measuring pretty easy and the 99mg of crushed powder added to my 8 gallon bowl completely reversed the hole phenomenon in my lotus leaves. It also resulted in an algae bloom, but that was relatively easy to bring under control (the bladder snails took it in stride.)


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## mistergreen (Mar 3, 2007)

johnwesley0 said:


> I can vouch for that. The tablet form made measuring pretty easy and the 99mg of crushed powder added to my 8 gallon bowl completely reversed the hole phenomenon in my lotus leaves. It also resulted in an algae bloom, but that was relatively easy to bring under control (the bladder snails took it in stride.)


Interesting about the algae. You can probably insert part of the tablet into the soil under the lotus like a root tab, reducing the chance of algae.


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## jatcar95 (Oct 30, 2019)

Btw, someone on this forum pointed me to this nutrient calculator, I've been using it to calculate dosage for chelated iron: https://rotalabutterfly.com/nutrient-calculator.php. There's a nifty option to specify using a "solution" that lets you specify the size of the container you're mixing in and the amount you want to does to reach a target. In the DIY ferts list you can specify KCl to figure out just how much you need to mix to reach a specific ppm.

Maybe overkill in this case, if it's a one-time dose. But still a helpful site nonetheless


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## YodelMogul (Oct 7, 2021)

dwalstad said:


> Be very careful adding that much potassium sulfate (K2SO4). Bacteria in the soil convert sulfates to toxic H2S, which can kill plant roots. Use KCl (potassium chloride) sold in grocery stores as a "salt substitute. And you don't need 20 ppm K. That high level is probably for high-tech tanks with CO2 injection and very rapid plant growth.
> 
> That said, the added K didn't solve your "holes in the leaves" problem, so I would either stop or reduce the K dosing.
> 
> ...


Thanks for the advice I will discontinue unless the other plants begin to show holes again. I was under the impression that plants consumed a decent amount of the sulphur and was improving the dose to see if the holes would eventually stop. I guess the hygro just isn’t my thing


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## YodelMogul (Oct 7, 2021)

jatcar95 said:


> Btw, someone on this forum pointed me to this nutrient calculator, I've been using it to calculate dosage for chelated iron: https://rotalabutterfly.com/nutrient-calculator.php. There's a nifty option to specify using a "solution" that lets you specify the size of the container you're mixing in and the amount you want to does to reach a target. In the DIY ferts list you can specify KCl to figure out just how much you need to mix to reach a specific ppm.
> 
> Maybe overkill in this case, if it's a one-time dose. But still a helpful site nonetheless


 Yes I found this somewhere and was using it. This is a really great tool!


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## YodelMogul (Oct 7, 2021)

So I’m still unsure does weekly dosing of either kcl or k2so4 lead to problems without doing water changes due to accumulation of chloride/sulphate. Some say the chloride is negligible and some say the sulphate is. I’ve seen many more people recommending k2so4 over kcl… 

Also, is it safe to fertilize my tank with kcl with emerald corys (brochis splendens)?


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## johnwesley0 (Feb 23, 2021)

YodelMogul said:


> So I’m still unsure does weekly dosing of either kcl or k2so4 lead to problems without doing water changes due to accumulation of chloride/sulphate. Some say the chloride is negligible and some say the sulphate is. I’ve seen many more people recommending k2so4 over kcl…
> 
> Also, is it safe to fertilize my tank with kcl with emerald corys (brochis splendens)?


One dose should go a long way for potassium deficiency. When I was having a problem, the pinholes ceased with subsequent new growth.


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## YodelMogul (Oct 7, 2021)

johnwesley0 said:


> One dose should go a long way for potassium deficiency. When I was having a problem, the pinholes ceased with subsequent new growth.


okay I guess I’ll sit back and monitor for awhile then. Particular fast growers (hygro and wisteria) didn’t seem to respond very well to K dosage so maybe something else is up.


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