Does anyone know why these leaves are growing warped?

[MichaelJ]

presumably because they were different water samples used for the hardness and calcium calculations.

It appears so as least for dGH. If I go by the quoted Mean values of Ca and Mg it comes out as (102.37 / 7.14 + 4.53 / 4.34) = 15.38 dGH. (max 16.48 dGH, min 14.54 dGH).

Cheers,
Michael

 

[MichaelJ]

Looking at the Hygrophila photo on a large monitor, rather than a phone, I think I can see magnesium (Mg) deficiency as well. It is the reticulated pattern (<"interveinal chlorosis">) on the older leaves towards the lower left hand corner. With magnesium deficiency you would get a fairly instant greening when Mg became available again. Deficiencies in mobile nutrient are much more difficult to diagnose because you have a lot more possibilities. The problem (and conversely advantage) with diagnosing all deficiencies is the <"assembly line nature of Liebig's limiting nutrient">, the problem is you have to find it, and the advantage is that when you do plant growth resumes.

Darrel, What deficiency are the holes in leaves normally associated with, if mechanical/predatorial damage can be ruled out? Some of the young leaves on my swords, crypts and frogbit occasionally gets these pin holes - I figure the holes appear very early on in the leaves development stage, because they just don't seem to suddenly appear on mature or older leaves - at least not in my case I believe. I don't really worry it about it, I am just curious why. I often read Potassium deficiency - very unlikely, but certainly not impossible, in that tank.

Cheers,
Michael

 

[dw1305]

Hi all,

Ahh, sorry, this may be a bit of trickery on my end - in the very top-left corner is 'hygrophila siamensis 53b', and in the bottom-left is 'Hygrophila polysperma 'Rosanervig'', the Rosanervig variant is supposed to throw out those white-veined leaves.

I can see that, now that you have told me!

What deficiency are the holes in leaves normally associated with

The pin-hole lesions are normally associated with <"potassium (K) deficiency">, but I think they may also be an early sign of iron (Fe) deficiency.

These are from <"Frogbit taken a turn"> and show iron deficiency induced <"Snake-bite lesions"> on Lemna minor.

My thought is that the damage was done to the new leaf and then can't be repaired, because iron isn't mobile within the plant, but only really shows as the leaf senesces.

cheers Darrel

 

[MichaelJ]

The pin-hole lesions are normally associated with <"potassium (K) deficiency">, but I think they may also be an early sign of iron (Fe) deficiency.

Thanks Darrel.

Cheers,
Michael

 

[eminor]

Expert already answered, i can only share my little experience. Using sand and hard water is that even easy plant will struggle, you can't miss a dose of ferts. Even with that you'll face deficiency, iron will have hard time as you can see in my journal (2-3 last pages).

In hard water + clay based soil, it's easier, you can grow lots of plant, not sensitive, at least not in perfect shape. With soft water + clay based soil you can grow everything. Back then i wanted to destroy dKH from my tap water, there was two solution, muriatic acid or RO water. Even if i like challenge, i'm not crazy enough to deal with Acid, that stuff is really dangerous. High CEC soil is such a pain relief, you can miss doses without issue

 

[_Maq_]

There are so many posts on ukaps claiming that hard water isn't an issue, but I'm definitely struggling to find other causes at this point, and Tom Barr himself has repeated that carbonates can impede plant health.

Don't mix hardness (essentially Mg & Ca content) and alkalinity (essentially HCO3- content).

What sort of dKH level would you deem acceptable?

Me, definitely less than 1 °dKH. (But my crypts grow poorly, I must admit.)
My suggestion: Try to dose LESS potassium.

 

[xZaiox]

Using sand and hard water is that even easy plant will struggle, you can't miss a dose of ferts. Even with that you'll face deficiency, iron will have hard time as you can see in my journal (2-3 last pages).

It's certainly feeling demoralising to me that I'm failing to grow plants labelled as 'easy'

With soft water + clay based soil you can grow everything.

Thanks for your input @eminor - I've decided to go the deionised water route. I've been using it for a little while now but I think I'm going to have to do a rescape - I'm fairly confident now that my Seriyu rock is messing up my water parameters. After changing water with RO/DI water, the tds and dGH + dKH readings drop (as expected), and then over the next few days they rapidly rise to what they previously was. I've taken a small sample of this rock and put it in a cup of deionised water, and the tds increases from it are staggering 😱 I'm never using this stone again lol

Me, definitely less than 1 °dKH. (But my crypts grow poorly, I must admit.)
My suggestion: Try to dose LESS potassium.

Thanks @_Maq_ - do you think 3-4 dKH is still acceptable? Also how comes the potassium suggestion? I've experimented with changing the doses from 30ppm to 20ppm, then down to 10ppm, I haven't really noticed positive differences, I think the pin-holes may be increased at the lower dose but in all honesty I'm not sure, the plants display pinholes even at 30ppm so it's difficult to tell. What potassium dosage would you recommend?

 

[_Maq_]

do you think 3-4 dKH is still acceptable?

Much better. Still, if not injecting CO2, such alkalinity would keep your pH above 7. Quite a many "demanding" plants would not take it. (Well-chelated iron may save some of them.)

What potassium dosage would you recommend?

I'm a keen supporter of ratios. There should be much less potassium than magnesium in the water. At the same time, the N : K ratio should be <=4 : 1 [molar!].
An example: I'm also running low-tech tanks. Recently, I front load 0.63 mg/L potassium, which means the actual concentration is even lower. No issues with potassium deficiency as long as I don't overdose nitrogen (eq. 3.5 mg NO3/L).
If your tap water is full of nitrates, then of course, your plants would be much more hungry for potassium, because nitrogen controls the speed of growth. Still, if you have, say, 20 mg/L nitrates, you don't need to have more potassium than 3.17 mg/L (4:1 molar ratio).

 

[xZaiox]

I'm a keen supporter of ratios. There should be much less potassium than magnesium in the water. At the same time, the N : K ratio should be <=4 : 1 [molar!].
An example: I'm also running low-tech tanks. Recently, I front load 0.63 mg/L potassium, which means the actual concentration is even lower. No issues with potassium deficiency as long as I don't overdose nitrogen (eq. 3.5 mg NO3/L).
If your tap water is full of nitrates, then of course, your plants would be much more hungry for potassium, because nitrogen controls the speed of growth. Still, if you have, say, 20 mg/L nitrates, you don't need to have more potassium than 3.17 mg/L (4:1 molar ratio).

Very interesting on the potassium dosing. My tap water contains about 20ppm of nitrates, but I will be diluting that to give me about 6-7ppm. I do, however, have a lot of fat fish so I'm assuming my overall nitrates will be a fair bit higher. When I was dosing the lower 10ppm of potassium, I didn't really see any benefits, but this is at the same time as increased hardness from the Seriyu rock, I'll give the lower potassium another go when I'm working with softer water