# Potassium deficiency ?



## art_b (Sep 2, 2006)

I need help identifying this deficiency. The new leaves of my bacopa australis are getting smaller, and the internode intervals are getting shorter. Is this potassium deficiency, excess, or what ?

I add 5 ppm K2SO4 every week after a 50% WC. I don't add anymore potassium during the week because KN03 and KH2P04 already have K when I dose them during the week. I used to add more a few weeks back which is about 9 ppm with WC, and an additional 2 ppm twice weekly. I cut down because I have more algae when I dose K2SO4 during the week.

Please confirm if this is K deficiency, or excess or something else. Please help me, please , I already have algae issues, and having nutrient deficiency is adding to my stress level.


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## trong (Aug 8, 2006)

a picture might help with identification. i didn't see how much kno3 you add?


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## art_b (Sep 2, 2006)

I still have to learn how to post pictures here at APC as I have not done it before here or any site in the interwebz. I will post pic soon.

I add about 2.5 ppm of KN03 every week to keep to 5 ppm. Also add KH2P04 to keep it to .5 ppm. I don't have to add more KN03 during the week as it stay at 5 ppm until my next WC. I sometimes add a bit more KH2P04 when P falls below .5 ppm. I also add a quarter teaspoon MgS04 which about .79 ppm magnesium every week. And as above, I add about 5 ppm K2S04 every week after 50% WC. 

I also dose Seachem Flourish, Flourish Iron, and Florish Excel. I don't have CO2.

Last week, I started dosing CaS04 and more MgS04 to increase my GH from 2 dH to 5 dH. I keep my KH to 2 to 3 dH.


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## Seattle_Aquarist (Mar 7, 2008)

Hi art b,

Here is a link to a site I use to help me diagnose any deficiencies:
http://www.finostrom.com.gr/images/aqua/fertilizers/map.htm 
Scroll to the right hand side of the page and about 1/2 down to find the deficiencies area.


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## PRESTON4479 (Dec 22, 2007)

art_b said:


> I need help identifying this deficiency. The new leaves of my bacopa australis are getting smaller, and the internode intervals are getting shorter. Is this potassium deficiency, excess, or what ?
> 
> I add 5 ppm K2SO4 every week after a 50% WC. I don't add anymore potassium during the week because KN03 and KH2P04 already have K when I dose them during the week. I used to add more a few weeks back which is about 9 ppm with WC, and an additional 2 ppm twice weekly. I cut down because I have more algae when I dose K2SO4 during the week.
> 
> Please confirm if this is K deficiency, or excess or something else. Please help me, please , I already have algae issues, and having nutrient deficiency is adding to my stress level.


That sounds like a really small amount of k. I look to get around 30ppm in the water weekly. The amount of k in no3 and po4 isn't really that much and I have never seen anything to show a relation between k and algae.

What kind of algae is giving you a problem?
What kind of lighting and tank size?


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## art_b (Sep 2, 2006)

After looking at the site, I think it is most likely K that is deficient. I will up my dose of KS04.

I have all sorts of algae. I head brown, fuzz, and one that I can't identify. A green stuff that disintegrates when I wipe it off the leaves. I thought it was the Flourish, and the Flourish Iron that was getting my algae out of control, so I scale down my dosage of them. Now that I have more algae, I'm not sure if I am dosing enough of them. Not having enough K may have contributed to more algae.

My tank is about 48 gallons (36x18x18 inch). I have T5 lighting 39 watts x 2 bulbs. I have them on for 8 hours. I used to have them for 10 hours, but scale them down to 8 hours last week to see if that helps with the algae.


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## Seattle_Aquarist (Mar 7, 2008)

Hi art_b,

Let us know how it goes!


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## art_b (Sep 2, 2006)

By the way, will my plant recover from potassium deficiency ? I mean will new leaves grow back to normal size ?


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## ShaneSmith (Feb 15, 2004)

Marginal chlorisis is common in potassium deficiency. Small new growth is probably Nitrogen or possibly a micronutrient.


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## art_b (Sep 2, 2006)

I doubt that it is nitrogen because I don't let it fall below 5 ppm. Maybe micronutrient, because I reduce my Flourish and Flourish Iron to see what is causing my algae. I still think that potassium is deficient because in addition to new leaves growing small, the older leaves are bending downwards, and the old leaves of my crypts have holes in them. 

I'll start dosing Flourish and Flourish Iron again using the recommended dosage and add more KSO4. Geez, I'm back where I started and still don't know what is causing my algae. I reduce dosing Flourish, Flourish Iron and KSO4 before because I thought it would reduce my algae. May it is phosphates that is causing my algae.


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## HeyPK (Jan 23, 2004)

Potassium deficiency shows primarily in the older leaves. If a lot of your older leaves have died back and the new growth is smaller, then it could be potassium deficiency. If the new growth is smaller without the older leaves dying, then it may be a nutrient whose deficiency symptoms show up primarily in the new growth, such as calcium, iron, or boron. 

Also, Magnesium deficiency is similar to potassium deficiency in many plants.


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## c4cache (Jan 21, 2009)

How to post photo's by John N.
note this will work with photo's on other sites to post here also, just a copy and paste from flickr.


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## prBrianpr (Nov 18, 2007)

Do a 50% WC and add 16-20ppm KNO3, 20-30ppm potassium, 1-2 KH2PO4. fertilize with micros like the product directions says. Add Iron to 0.3 ppm max. Do not add H2PO4 the same day as the micros and iron. Use good Co2 levels and scrape all the algae. Lightly syphon the gravel. This should resolve all your problem in a week or two. remember 50% WC and add fertilizer 1 day per week o per 2 week depends on your aquarium bio mass.


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## art_b (Sep 2, 2006)

I don't have CO2, I only used Excel. So I guess I'm CO2 limited. When I bumped my phosphate to 1.0 ppm by adding KH2PO4, I had more algae that week. Then blue green algae appeared (the one algae that I could not identify before). I also suspected that I have too much or too little of the other ferts such as potassium and micronutrients.

After a week I change 50% water, and I did not dose any KH2PO4. I only dose minimal Flourish and Flourish Iron for that week. My algae including the BGA did not grow that fast, but so were my plants. The crypts kept growing new leaves though. But by the end of the week, my nitrate jumped up from 5 ppm to 10 ppm which is not normal considering I did not dose any KN03 for that week. This might mean I'm now also phosphate limited. (Or maybe potassium limited ?) 

This week, I change 50% water, dosed 15 ppm KSO4, Flourish, Flourish Iron. I kept my GH to 5.5dH with around 30 ppm calcium and 6 ppm magnesium. I also dosed 0.15 ppm KH2PO4. My nitrate is 5 ppm. I will keep my phosphate level at around 0.2 ppm and see how it goes. My nitrate should at least be the same or go down, but not go up. I will dose KN03 if needed.

I also put a powerhead to increase water flow, and treat the BGA with erythromycin.

It is now Tuesday, and I can see that algae is starting to grow on the side glass. Oh dear :-s.


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## armedbiggiet (May 6, 2006)

How about not putting any thing and just do water change for a while? I only add stuff when the plants needed... more like monthly or less. After everything back in normall than put what ever you like.


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