Potassium deficiency?

[dan4x4]

Hi I'm guessing the pics below are a potassium deficiency. But Im not sure. I'm dosing dry ferts. EI method, got my salts here http://www.aquariumplantfood.co.uk/fertilisers/dry-chemicals/dry-salts.html?limit=all

I have bumped up the dosing of macro and micro to 30ml a day. separate micro and macro days.

I did a water test
PH 6.8
KH 3 degrees
GH Over 16 degrees
NO2 - 0
NO3 50PPM

Low tech planted aquarium. 30% water change weekly. Some algae in the tank but you really have to look for it.

Flow is between 7-10 times the volume of the tank through the juwel ecco pump and also a jecod wave maker (please note the wave maker is on a constant flow not wave).

Lighting was 4 hours on a morning 8-12, then 6-10. However i have increased the light recently by an hour on the evening to see if this makes a difference.

Stock in the tank is 10 tiger barbs who are fed well, 5 cherry/bee shrimps, immigrant snails that sneaked in on plants.

 

[dan4x4]

a.

 

[dan4x4]

all plants are affected, it was water lettuce first. then everything else, echinodours, sagittaria, aponogeton, crpyts. Actually Crinum and Littorella uniflora dont seem affected.

 

[zozo]

Could be.. Java fern is a bad indicator plant, not because it's a slow grower, it tends to die off older leaves by nature, looking like it gets depleted from mobile elements. But it's more a plant characteristic to do that. Water letuce is a plant also demanding a lot of light, indoor this is a rather difficult plant and could show deficiencies because of light deficiency while it grows older and bigger. So also this plant can be distracting as indicator use. Frogbit would be a beter choice.

Anyway, Potassium is a pretty harmless element, so it is a very easy and safe to add extra. If you take K2SO4 and add 2 grams on a 100 litre, you'll add about 10 ppm K. It can't hurt to add some extra.

 

[dan4x4]

Could be.. Java fern is a bad indicator plant, not because it's a slow grower, it tends to die off older leaves by nature, looking like it gets depleted from mobile elements. But it's more a plant characteristic to do that. Water letuce is a plant also demanding a lot of light, indoor this is a rather difficult plant and could show deficiencies because of light deficiency while it grows older and bigger. So also this plant can be distracting as indicator use. Frogbit would be a beter choice.

Anyway, Potassium is a pretty harmless element, so it is a very easy and safe to add extra. If you take K2SO4 and add 2 grams on a 100 litre, you'll add about 10 ppm K. It can't hurt to add some extra.

Thanks again Zozo. Ill do it now

 

[dan4x4]

I don't have it, i have..

KH2PO4 - Potassium Phosphate
KNO3 - Potassium Nitrate

and

MgSO4 Magnesium Sulphate

Would of of the first 2 suffice?

Thanks

 

[zozo]

Get it... !

Look at this..
http://www.theaquatools.com/fertilization-calculator

Add litres and grams to add.. Than see bellow to amounts added.. You would need to add quite a lot of KH2PO4 to add a little K. In the long run i'm not sure that will work for a assumed K deficiency.. Because you would add more PO4 than K..

 

[AverageWhiteBloke]

I'm no expert in deficiency but could this be antagonism of some kind? Not sure which excess of what would cause it.

Low tech planted aquarium. 30% water change weekly. Some algae in the tank but you really have to look for it.

I find it hard to believe that dosing EI in a low tech with 30% changes that you would end up def in K. Water is very hard as well so maybe preventing something else. I do 50% in highish lighting and not even full EI and haven’t came across any potassium issues before. Dosing full EI in a low tech with those WC's I'd imagine there's quite a build up.

 

[dan4x4]

OK obviously no expert in this but has anyone added ash, as in the left overs from burnt wood to the tank, apparently it is a source of potassium?

 

[dan4x4]

I'm no expert in deficiency but could this be antagonism of some kind? Not sure which excess of what would cause it.



I find it hard to believe that dosing EI in a low tech with 30% changes that you would end up def in K. Water is very hard as well so maybe preventing something else. I do 50% in highish lighting and not even full EI and haven’t came across any potassium issues before. Dosing full EI in a low tech with those WC's I'd imagine there's quite a build up.

When you say antagonism, like another nutrient within the tank is preventing the uptake?

 

[AverageWhiteBloke]

Yeah mate. Not sure how it all works but apparently it happens. Are you doing EI at full values? Maybe this image would throw some light on it. Not sure of which way the arrows go though.

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[dan4x4]

Yeah mate. Not sure how it all works but apparently it happens. Are you doing EI at full values? Maybe this image would throw some light on it. Not sure of which way the arrows go though.

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lol yeah this is confusing, I'm going to order some K2SO4. See if that works first. fingers crossed

 

[AverageWhiteBloke]

What about co2. I'm assuming when you say low tech you mean you have none or LC? What lights you got swinging above there and how long they on for? From what I gather your co2 will be coming from natural gas exchange with weekly changes maybe most is gassing off and your plant mass has hit a point where it's fancying a bit more carbon.

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[AverageWhiteBloke]

Haha yeah confusion reigns, with ref to the chart I'm assuming that you would work backwards on the arrows. I.E we know that phosphate and Iron don't get on so if you look at the chart arrows in both directions so too much iron causes issues with po4 and vice versa so your case k has issues with magnesium, boron, nitrogen , phosphate and calcium. So in a tank with high hardness and too many ferts it may be in the frame. Or carbon lol.

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[AverageWhiteBloke]

I hope the pot sulf works for, there's quite a lot of k in kno3 compared to kh2po4 so maybe dosing a bit more kno3 for now may help but like I said even people with high light tanks don't bother with K unless the dose po4 and kno3 leaner then supplement with a bit of k to make up the difference.

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[zozo]

I do because i get > 25ppm N from the water company, according to them, rather more then less in my region.. Together with feeding and fish pooping around i estimate i have enough of that. I skipped adding KNO3 and only add little KH2PO4, enough K2SO4 to have at least an extra 10 ppm and trace elements.

Anyway my Hygroryza arista grows and colors much beter with this new regime.. Before with adding KNO3 it didn't.. And before that with a complete fert it also didn't..

 

[AverageWhiteBloke]

I have just started adding a touch of K in my dosing. Not sure if I needed it or not, I recently bought some Blue Rams which prefer soft water. I have soft water out of my tap, V soft in fact 39 TDS but my TDS was getting up there @ 250> in the tank with 50%+ wc's on a weekly basis and the odd random 25% when I got the time. My tapwater according to the water company has no nitrogen but about 2ppm phosphate which they add to remove iron. Bought myself some duck weed and over the last month or two have started reducing my salt dosing to the point where my TDS is levelling out between WC's and currently dosing about a third less than I was. Duck weed looks fine but I did have some holes appearing in leaves on some S.Repens, can't blame definitely potassium because I let the repens grow too dense and clipped them right down to the base so it may be just light starved down there. Added a touch of K via pot sulphate just to make sure, I'll see how this pans out but being quite heavily stocked with fish I don't think there is a nitrogen issue yet, I don't think I'll go any leaner for now.

I knocked the below up when I was reducing dosing by a couple of mil per week just to get an idea of when K may start becoming an issue, it is based on the amount of K derived from dosing KH2PO4 and KNO3 at EI levels with no added K. As you can see you can come down a fair bit in dosing before K would start becoming something one would consider as bordering in deficient. Hence my assumption antagonism may play a part in the OP's issues IF that's what it is, we don't know the lighting and carbon setup yet. With my lighting and co2 dosing and not experiencing any K issues all the time I was dosing EI at top end combined with my plant mass and floaters sucking out a fair bit of nutrients I can't really see how the OP would be experiencing a lack of potassium, you never know though. Looking at Mulders chart though an excess of NO3 and PO4 could supposedly prevent uptake of K and if I was dosing too high with my setup and getting a build up of left over ferts could the OP be in the same boat? Only way to find out would be larger water changes for a while to see if this improves the situation and definitely some LC to cover the carbon if none is in there. I've came down to 15ml per dose from 20ml which as you can see still puts me in K EI threshold.

 

[zozo]

That's a nice log you made there..

 

[AverageWhiteBloke]

That's a nice log you made there..

Haha, Thanks, I have my moments. And very easy to remember 40/4 when mixing my bottles. Should have put Magnesium on there I guess but I find 1 level teaspoon is circa 5 grams of epsom salts and 5 grams=5ppm in a 100ltr tank the threshold for Magnesium being 5>10ppm. Anything that takes a bit of head work out is good for me.

 

[zozo]

What about the statement you can read at most aquarium fert related articles. That if gH is above 4 we likely do not need epsom?
Ever since i'm kinda asking myself, should i still add for the sake of whatever?..