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Discussion Starter · #1 ·
Despite decent Ca levels as written in the tittle i still have severe burned and stunted tips on my Umbrosum and Alternatera reineckii. Those symptoms go away when K is almost 0 ppm but at the same time K deficiency shows up (at 0 ppm K plants begin to grow healthy in only 3..4 days time). Many say that the problems with stunted/burned tips are due to low NO3, CO2 etc. but i checked all that stuff and i can say that is NOT the case; it didn't helped at all. I tried high NO3, high PO4, Mg, changed micro ratios and levels (the only micronutrient i didn't change was copper but i don't think it would have any effect) I also tried low levels of SO4, Na. I wonder HOW some of us can have high K and low Ca and no problems i've just written about. If there is someone who can explain in simple words what causes such issues and it really helps he should be given "Planted Tank Nobel Prize"
 

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Discussion Starter · #6 ·
I went even further with that; i even checked other elements and how they will affect my plants to find what's wrong. I dosed the following:

- nickel (NiCl2 * 6H2O)
- cobalt (CoCl2 * 6H2O)
- iodine (KJ)
- vanadium (from a commercial fertilizer)
- urea (CO(NH2)2) - as a source of N
- guanidine carbonate (C2H10N6 * H2CO3) - as a source of N
- ammonium nitrate (NH4NO3; 0.5 ppm MH4 daily)
- 0 ppm Mg & 30 ppm Ca - Mg deficiency began to show on Cardamine Lyrata (its leaves curled upward along leaves edges - it's another sign of Mg deficiency apart from yellowing lower leaves)

All that stuff didn't help at all. Tom Barr said it was impossble that K+ blocked Ca even when K+ was high but my experiments showed that it wasn't true.
But one thing is certain: stunted growth of fast growing stem plants is a result of Ca blokage. I came to the conclusion that it would good thing to dose K+ daily in small amounts but whenever K+ drops below 5..10 i notice some improvement but K+ deficiency apperars on other plats :(
 

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Discussion Starter · #10 ·
Elkmor said:
Try boric acid, dose 0,02 mg/l of boron weekly. If it doesn't help then suspect lots of boron in your tap water... do less water changes, try PPS without w/c for a month.
I did it but plants stopped to grow a few days after adding boron. I use only RO water so all the micros are under control. I also stopped adding micros for a few days but plants began to grow pale.
 

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Discussion Starter · #12 ·
Well, i believe that the chemicals you mentioned above can cause the problems i have. But i don't think there is any source where they could come from. Of course i agree that RO doesn't remove chemicals from the tap completely.
I have problems with 2..3 species only; others seem to grow much better. The problems concern stem plants only. Such plants like Blyxa japonica, h.callitrihoides, rotala, microsorium, aromatica grow very well.
The only chemicals i add to my tank come from TMG and RO water reconstitution such as CaCO3, MgSO4, NaHCO3, KNO3, KH2PO4 and Ca(NO3)2 so these are salts we all use in our tanks and i'm quite sure there don't cause any problems if used correctly. I know for sure that something is blocking Ca in my tank and this is the only issue i have now and try to find out how to solve it.
 

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Discussion Starter · #14 ·
First of all i'd like to thank for all the people from APC as it helped and helps me a lot :)
Of course i will post any new info from experiments in my tank. When it comes to chelators i tried only ones which were a blend of EDTA + DTPA. I add Fe and Mn chelators to changed water so that Fe was at the same level all the week (0.2..0.3 ppm). It helps a bit.
 

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Discussion Starter · #16 ·
Yes, I also notice that. It also seems higher NO3 helps a bit maybe because when there is more N plants need more K. I'm very confused about NO3 as i measured it using 2 test kits: one of them showed 20 ppm but the second one - 10 ppm (i know we cannot rely upon test kits but JBL test kit i always used gave accurate readings. This time however something's wrong with it)
I made reference solution of known NO3 (20 ppm) and one showed below 5 ppm one 10 ppm. I got furious and took water sample to a laboratory and told them to measure NO3 accurately. I hope the result will be in several hours.
 

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Discussion Starter · #17 ·
One more thought came to my mind... In the past when i didn't have any problems i had very low PO4 and NO3. There were about 0.1 and 2..5 ppm rescpectively (i had issues with N deficiency and my cabomba didn't grow - it was yellow on its lower leaves) Also it was only 13 ppm Ca and 4 ppm Mg. K was about 15 ppm. Plants grew like crazy. After switching to high PO4 and NO3 the problems i described occured. Is it possible that having low PO4 and NO3 it puts much lower demands on Ca ? Also, as far as i know NO3 is converted to NH3 in plants. From the hydroponics i know that ammonium excess also induces Ca deficiency. So maybe high NO3 produces ammonium excess in plants which causes Ca deficiency but it could be an idle speculation...
 

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Discussion Starter · #21 ·
OK guys, let's see what happens after lowering PO4. As Defdac has already said it seems it helps. Anyway, now i'm going towards low levels (at least PO4). A year ago i had 2..5 ppm NO3 and not detectable PO4 (say 0.1 ppm max) and plants grew like crazy; no burned, stunted tips, no deformed leaves. At that time i didn't know the word "nutrient deficiency"
 

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Discussion Starter · #24 ·
I used commercial NPK fertilizer which consisted KH2PO4, KHCO3 and very little NH4. I estimated i had dosed about 1.5 ppm K daily. I didn't know what the exact K level was in the water column but i think it was about 10..15 ppm. I emphasize that the strange thing was that despite low Ca (about 13 ppm) and "decent K", i didn't have issues with twisting, deforming etc. Plants grew faster at low PO4 and NO3 levels than they do now at high ones. I think that dosing too high PO4 we just give our plants a "painful kick" making them unable to take enough amounts of Ca (it doesn't mean i'm right but if lower PO4 helps - and i hope it will - i will no longer dose high PO4). On the whole it seems to me Edward's suggestions and PPS method are better and safer than EI.
 

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Discussion Starter · #26 · (Edited)
So, i see clear improvement now:

- NO deformed leaves on alternatera reineckii
- fewer burned tips on umbrosum

All things happened when i stopped to dose NO3 form Ca(NO3)2... When NO3 was 5ppm plants began to grow healthier. I didn't change K levels. It's 10 ppm all the time.
However the total growth is not too fast yet. Maybe Ca(NO3)2 is not very good source of NO3 (as i remember Edward reported he had issues with Ca(NO3)2 salt)
The strange thing is that i see higher demand for iron now; i have Fe deficiency (pale and white leaves on umbrosum, pale leaves on Blyxa japonica). I added 0,2 ppm Fe and 0,1 ppm Mn and Blyxa is recovering from the deficiency. At the same time i noticed EDTA Fe chelator is not very good.
 
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