Chlorosis - Light or Nutrients Limiting?

[geoffrey]

Good Afternoon,

Noticed very frequently that bottom leaves of my relatively healthy plants have chorosis and subsequently melt or break. Is that a sign of inadequate light since the rest of the plant is healthy? Will those unhealthy leaves at the bottom become an algae magnet? Are there any other tell-tale signs to help differentiate problems due to limiting light from limiting immobile nutrients?

[David]

Hi Geoffrey

I would believe you are speaking of stemmed plants? If it is, take alook at the bottom section. If it is relatively darker then the surrounding, chances likely it is shading off due to insufficient light unless the top section is turning yellow or translucent.

If it is stemmed plants you are refering to, perhaps you are planting them too closely. It is always best to plant them leaf tip to tip. However in this method, the insufficient light situation will still happen but it will take a longer time.

Remedy is to remove the whole plant, cut off the bottom section and replant the top.....

[geoffrey]

Yes David, they're stem plants. Hard to keep the bottom leaves intact. But what puzzles me is, in some tank that I've seen, their bottom leaves are in great condition even when they are shaded. Always wonder what the experts use on their plants to help them compensate for the limited light?

[Simon]

I guess it all depends on what type of lights and how much of lights that makes a different, and also some species of plants tend to be more demanding and readily melt without sufficient light

[vinz]

Geoffrey, I've always wondered that too. In the type of tanks you mentioned, I've noticed one thing my tanks don't have... low temp, usually at the 26 celcius mark.

[geoffrey]

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On 1/17/2003 10:54:01 AM

Geoffrey, I've always wondered that too. In the type of tanks you mentioned, I've noticed one thing my tanks don't have... low temp, usually at the 26 celcius mark.
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Same!!! The only different I noticed is the temp too. Some books mentioned lower temp slow down the growth rate of plants even when you have lotsa of light. Could it be the slower growth rate helps maintain those bottom leaves?

[Addie]

Hi, I have noticed that my red plant (Ludwigia palustris, not sure the exact name. could be arcuata or Red 3 or Mexico) will have bottom leaves drop-off more than my Hygrophila polysperma although it seems to me that both are planted densely. Does anybody have this observation before in their plants and any known reasons or hyphothesis?

[vinz]

I'm not familiar with growing Ludwigia, but H. polysperma can grow in moderate light, so that could be a difference.

[FC]

I have 2 Ludwigia species for the past 2 months. It is not the temperature.

I made very close observation to them and they behave this way:

1) when there is bright light and at the same time PO4 is in deficiency, they will turn red to dark brown.
2) once the plants turn dark brown or red, do not cut it, quickly add PO4 to the root area, they will turn greener in about 3 to 7 days, starting from top leafs. The bottom leafs may not fully recover.
3) cutting dark red/brown plant and re-plant the top will kill the plant in 10 days time. Leafs drop till botak and then stem melt and float up.
4) adding PO4 to the root will keep all lower leafs green and stay healthy even in low light. The top leafs are slight hue of red & orange

Look at the "expert" tanks that you mentioned again. You would realise that some have hair algae on the stem plants. This is due to overdose of PO4.

That's the secret I discovered!

[vinz]

FC, this secret applies to all(most?) plants or just Ludwigia?

[FC]

I cannot say to all plants (my ecounters are limited) but I beleive it is relevant to all stem plants, especially the demanding ones.

I used to be happy about my plants being red but after my own mishaps, I had thought otherwise. If you observe closely, the only stem plants' leafs that drop are those that is unsually red/brown which is the sign of PO4 deficiency accordingly to my experience and an article (illustrated with photos) that pointed me to that. No green leafs would ever drop unless interfered by creatures in the tank.

I would appreciate if anyone found it differently and feedback as a mean to correct myslef.

[David]

Hiya FC

Thanks for the info....I'll give it a go...is there any dosage involved for this?

[vinz]

Noticed that the shaded leaves for the H. polysperma in one of my tank do not shed... that tank used to have high PO4. Given the algae problems I have with it now, it probably still is. Will measure and feedback.

My other tank, the H. Polysperma is losing a lot of lower leaves and that tanks is low on PO4.

Looks like its time to finish that pack of Jobe sticks.

FC, any reason why you inject instead of using N-P-K sticks, other then precision dosing?

[FC]

I inject into the substrate for:
1) treating the deficient plants only which would absorb them quickly.
2) I can better control the PO4 level, slower release into the water. I beleive the "expert" tank do not have time for it and just pour into the water column which result in hair algae commonly seen in his tanks.
3) like you said, precision dosage to avoid over dose
4) I have never use NPK sticks before, sounds like a good idea.
5) important: when I do that, I also take along KNO3, Flourish and Fe with it into the substrate (AS DEEP AS POSSIBLE). Minority will be taken up by the roots and the rest will be seep out into the water column. You can measure that with test kits after about 2-3 days.

But not KSO4, I add it into water because:
a) I prefer it to be in water, ready for any excessive PO4/NO3 there.
b) KNO3 has sufficient K for its' job in the substrate. (Diana Walstad: plant take in about 320mg N, 28mg PO4 and 160 K to produce 20g of new plant parts. I therefore assume the intake is also in similar proportion)

Dosage:
I prefer a conservative (safe) way. I realised that for plant to absorb neutrients more efficiently, there is a need for balance and certain trustholds.

Sorry to be continue, I got to go out (family waiting).

[geoffrey]

Thanks for your tip and don't keep us waiting FC. Like David, will give it a shot.

[DEA]

*cough*

i don't get why one would want to inject nutrients into the substrate
technically speaking
1. substrate already contains all the nutrients the plants need (walstad's school of thought)
2. even if the substrate doesn't, the water flow through the substrate will bring nutrients in that are held by the gravel pending on CEC (amano school of thought)

so, basically, i don't see a point

[Addie]

Hi FC and Vincent,
Thanks for sharing your experiences. FC observation is very interesting. I would like to give it a try too.

FC, May I know what is the PO4 solution that you are using? I only know Seachem Phosphate which recently introduced into Sgp market. Do you use those for normal plants?

[Addie]

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On 1/18/2003 11:33:58 PM

*cough*

i don't get why one would want to inject nutrients into the substrate
technically speaking
1. substrate already contains all the nutrients the plants need (walstad's school of thought)
2. even if the substrate doesn't, the water flow through the substrate will bring nutrients in that are held by the gravel pending on CEC (amano school of thought)

so, basically, i don't see a point
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Does the water flow through the substrate or gravel? I thought it doesn't if there is not undergravel heating tube (convection) or other mean of forcing the water flow through the substrate or gravel.
Er... I'm still learning. Appreciate your help to clarify

[FC]

Ok, I am finally free. Beleive me, parenting is no joke, I seriously need re-thinking on how I handle things at home, to be more effective.


"i don't get why one would want to inject nutrients into the substrate
1. substrate already contains all the nutrients the plants need (walstad's school of thought)
2. even if the substrate doesn't, the water flow through the substrate will bring nutrients in that are held by the gravel pending on CEC (amano school of thought)"

Hi David,
Just like liquid fert, base fert has all nutrients necessary for most plants growth. But we forgot something:
1) the recipe called for application to wide range of plants.
2) the base fert nutrients are slow release type and may be too slow for plants who are in certain deficiency, needing quick cure.
3) they are conservative on PO4 and NO3
4) the fert trusthold may not be enough or excessive and not always balance.
5) if they are omni effective, we would not have problems.
6) fish waste is not very useful because they contain various unknown chemistry depending on the food fed, the fish species, fish's health, etc. The problem in short is lack of consistancy and balance in chemistry. Walstad encounters are based on certain fishes kept that were fed with certain dry foods that happened to have the right result altogeher. I beleive her formulae are only limited to low light plants and for easy-going people who does not demand alot on tank's and plant's look (a little dirty and thin plants).


Most important of all, "how well we want our plants to be?quot;. AQ forumers and moderators alike are always looking for higher ground. Count me in, and that is hobby to me.

[FC]

Hi Addie,

I use KH2PO4, Seamchem has the same thing for its' Flourish P. Flourish N contains both NO3 and ammonia in a form they claimed accessible by plants but not algae. I have not tried them because I happy with KH2PO4 and KNO3 so far.

Without heater, water do circulate in the substrate by:
1) diffusion (there is always unbalance in chemical concentration between substrate and water column, water change add to that effect) is a powerful water mover. Remember how perfume flow in a room? Example. I do inject liquid fert into the substrate, after 2-3 days, my testers show me that there is PO4, NO3 and Fe.
2) convection. Most of us have fan blowing on the water surface. Therfore the cool water flows down into the substrate in exchange for the warmer temp there (sorry should be the other way round, heat always travel towards cold).