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Echinodorus bleheri - stunted growth

John P Coates

John P Coates

Member
Joined
21 Feb 2014
Messages
164
Location
Bracknell
Hi Folks,

I'm having a problem with the only E. bleheri in my tank. It doesn't seem to want to grow but is otherwise healthy. I have several other plants, all of which are growing rapidly. These include Bacopa compacta, Echinodorus chrileni and Hygrophila guianensis. The substrate is Tetra Complete topped by JBL Manado. Inserted into the substrate immediately at the base of the E. bleheri is a JBL Kugelin micronutrient ball. Water temperature is 25°C, KH is 5°dH and GH is 8°dH. Lighting is 70 PAR. CO2 concentration is typically 15ppm. I dose the tank with a combination of Tropica General Fertilizer and Tropica Specialized Fertilizer.

I am not a biologist but I have come across the term allelopathy. Is it possible that there is another plant in my tank that is suppressing the growth of the E. bleheri?

JPC
 
Well your CO2 looks very low for a par that high, Ceg also says that the ways we measure CO2 often over-estimate. Hm I've just thought at what height in the tank water was the par measured, if at the surface it should be fine if at substrate it is very high. BUT you say all your other plants are growing well so, perhaps the bleheri is just more demanding than any other plant is in the tank so while others cope it suffers. Echinodorus are heavy root feeders, perhaps requiring substrate npk as well as trace and ei...
That's what I can think of, I hope it can be of some help.
 
Crossocheilus said:
Well your CO2 looks very low for a par that high, Ceg also says that the ways we measure CO2 often over-estimate. Hm I've just thought at what height in the tank water was the par measured, if at the surface it should be fine if at substrate it is very high. BUT you say all your other plants are growing well so, perhaps the bleheri is just more demanding than any other plant is in the tank so while others cope it suffers. Echinodorus are heavy root feeders, perhaps requiring substrate npk as well as trace and ei...
That's what I can think of, I hope it can be of some help.
Click to expand...
Hi,

Many thanks for your suggestions.

I agree that my choice of CO2 concentration is only half of that normally recommended but I am hesitant about increasing it as all the other plants are growing rapidly. The PAR figure was measured at the top of the E. bleheri. Perhaps your comment about this plant being a heavy root feeder is the key. What is the best way of providing extra NPK at the roots? Presumably root tabs of some kind? JBL Kugeln does not provide either N or P, nor is there any of these macronutrients in Tetra Complete. I think you may be onto something - thank you.

JPC
 
Well I know soil substrates like ada aquasoil provide npk, however that isn't a practical solution, I would suggest searching around to see if there are any root tabs that provide npk. Otherwise perhaps upping the liquid fert regime will help.
 
How long has it been in the tank?
Swords can have huge rootsystems, though feeding through the leaves is enough for them. Basically swords are quite easy, not needing high light. Extra feed can be done with capsules with osmocote, or freeze some osmocote in icecubes to push under the substrate, or i used a syringe to inject ferts under the substrate. Basically i just think it may need some time to get established. Allelopathy is written about but i never heard about it in aquaria.
 
When you say "stunted" does that mean it doesn't grow at all, or does it grow stunted new leaves, discoloured new leaves, does it look like having any other issues with older leaves dying, holes, melting, etc?
Lower CO2 will not stop growth, it will slow growth down, maybe cause other issues like algae but will not stop the growth of the plant as long as there is some co2. One has to run out of co2 completely to have plants stop growing which is kind of impossible.
If new leaves are not appearing at all you have a nutrient element missing, constantly going down to 0 and this sort of deficiency appears on most sensitive/most demanding plants. As already suggested, if micronutrients are provided I'd increase N, P and K. I'd dose the water column, easiest and the most sure way all plants get it because even if they are not showing anything yet, they will, if not visible damage/stunting, in the form of algae around the tank.
 
Crossocheilus said:
Well I know soil substrates like ada aquasoil provide npk, however that isn't a practical solution, I would suggest searching around to see if there are any root tabs that provide npk. Otherwise perhaps upping the liquid fert regime will help.
Click to expand...
Thanks again. The only readily available root tabs with NPK are those supplied by API. The alternative is Tropica capsules but few suppliers have them in stock. I distinctly get the impression that root feed would be better but I'm only guessing.

JPC
 
Edvet said:
How long has it been in the tank?
Swords can have huge rootsystems, though feeding through the leaves is enough for them. Basically swords are quite easy, not needing high light. Extra feed can be done with capsules with osmocote, or freeze some osmocote in icecubes to push under the substrate, or i used a syringe to inject ferts under the substrate. Basically i just think it may need some time to get established. Allelopathy is written about but i never heard about it in aquaria.
Click to expand...
Hi Edvet,

Yes, it's odd that I'm having a problem with an 'easy' plant. It's been in the tank for four months. Presumably some plants rely on root feed more than foliar feed. That's well outside my current knowledge. Allelopathy would appear to exist in aquaria. Diana Walstad in her book 'Ecology of the Planted Aquarium' talks about it. And this is an interesting link:

http://www.barrreport.com/showthread.php/4355-Cryptocoryne-Wendtii-and-Allelopathy

The above is of particular interest as I also have C. wendtii (petchii) growing in my tank.

EDIT: on reading the above link, it looks like allelopathy is not the likely cause.

JPC
 
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sciencefiction said:
When you say "stunted" does that mean it doesn't grow at all, or does it grow stunted new leaves, discoloured new leaves, does it look like having any other issues with older leaves dying, holes, melting, etc?
Lower CO2 will not stop growth, it will slow growth down, maybe cause other issues like algae but will not stop the growth of the plant as long as there is some co2. One has to run out of co2 completely to have plants stop growing which is kind of impossible.
If new leaves are not appearing at all you have a nutrient element missing, constantly going down to 0 and this sort of deficiency appears on most sensitive/most demanding plants. As already suggested, if micronutrients are provided I'd increase N, P and K. I'd dose the water column, easiest and the most sure way all plants get it because even if they are not showing anything yet, they will, if not visible damage/stunting, in the form of algae around the tank.
Click to expand...
Hi SF,

OK, by 'stunted', I possibly used the wrong word but, in a way, it's correct. There are few new leaves appearing and, when they do, they grow very slowly. The new leaves are of a nice, lush green with no visible defects of any kind. Since nitrogen is required for leaf growth, I suspect a nitrogen deficiency. There may also be a phosphorus deficiency for root growth but I would have to uproot the plant to check that!

Do you know if aquatic plants absorb nutrients equally well through the roots and leaves?

JPC
 
John P Coates said:
Presumably some plants rely on root feed more than foliar feed.
Click to expand...

I don't think that's true and at least in relation to Potassium is quite the opposite which is taken mostly through the water column/leaves.
The reason for providing root fertilisation in terms of rich substrate instead of water column feeding is a debated topic and in my opinion has to do mostly with the fact that algae can't feed on nutrients in the substrate and only plants can. But algae feeds on organics in the water column and plants can't so either way neither method is a guarantee of anything in terms of algae.
 
Better through the leaves even, shorter route. Heavy rootfeeders are a misnomer, they feed through the leaves better. Swords occur in areas prone to heavy flows due to heavy rainfall, thus requiring a large rootsystem, just to stay where they are:). We can abuse that by feeding through the roots and not through the leaves, though the newer insights (EI) make that unnessecary.
 
John P Coates said:
The new leaves are of a nice, lush green with no visible defects of any kind. Since nitrogen is required for leaf growth, I suspect a nitrogen deficiency.
Click to expand...

Nitrogen deficiency manifests itself by deteriorating old leaves. It's a mobile nutrient meaning when it is in shortage, plants extract it from old leaves in order for the new ones to grow.
Occasional nitrogen deficiency manifests in normal new growth, but old growth gets some sort of damage, mostly necrosis from the tips spreading to the base or yellowing of leaves.
When it zeros out, as with any other nutrient, growth will stop. When it is deficient for a long time, new growth will be stunted, meaning new leaves will be smaller in size, along with damage on old leaves, not just stunted new growth.
Potassium manifests itself with holes on old leaves, necrosis/melting of entire leaf along with the initial holes, subject to plant species and tank how far it is left go.
Phosphorus is an unlikely one in any tank because it comes from everything, tap water, fish food is loaded with it. But its harder to pinpoint, but is also mobile, so old leaves will be affected same as N and K.
 
sciencefiction said:
Nitrogen deficiency manifests itself by deteriorating old leaves. It's a mobile nutrient meaning when it is in shortage, plants extract it from old leaves in order for the new ones to grow.
Occasional nitrogen deficiency manifests in normal new growth, but old growth gets some sort of damage, mostly necrosis from the tips spreading to the base or yellowing of leaves.
When it zeros out, as with any other nutrient, growth will stop. When it is deficient for a long time, new growth will be stunted, meaning new leaves will be smaller in size, along with damage on old leaves, not just stunted new growth.
Potassium manifests itself with holes on old leaves, necrosis/melting of entire leaf along with the initial holes, subject to plant species and tank how far it is left go.
Phosphorus is an unlikely one in any tank because it comes from everything, tap water, fish food is loaded with it. But its harder to pinpoint, but is also mobile, so old leaves will be affected same as N and K.
Click to expand...
Hi SF,

Many thanks for your reply.

I think I can safely say, based on your information, that there is not a potassium deficiency. But there could be a phosphorus deficiency. I use RO water to which I add minerals but they do not contain any phosphorus compounds. Secondly, I use a low phosphate fish feed. Thirdly, using the JBL phosphate test kit, PO4 is often less than 0.02ppm. Similarly, using the NT Labs NO3 test kit, nitrate hovers around just 5ppm.

JPC[DOUBLEPOST=1409140978][/DOUBLEPOST]
Edvet said:
Better through the leaves even, shorter route. Heavy rootfeeders are a misnomer, they feed through the leaves better. Swords occur in areas prone to heavy flows due to heavy rainfall, thus requiring a large rootsystem, just to stay where they are:). We can abuse that by feeding through the roots and not through the leaves, though the newer insights (EI) make that unnessecary.
Click to expand...
Hi Edvet,

Gosh! This is excellent. I am learning so much.

So, it looks like I don't need to add NPK-containing root tabs. I'll use the newly-purchased Tropica Specialist Fertilizer more frequently (which includes N and P). I'm slowly becoming more confident adding N and P and seeing that I don't have an algae problem!

JPC
 
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It could be. Do you have a picture of the plant in question maybe? Even with phosphate, old leaves should show some sort of damage like chlorosis/necrosis. If old leaves are ok and healthy, then you've got a micro nutrient deficiency. It only manifests in no growth or new growth showing some sort of damage depending on the type of micronutrient, as micro nutrients are not mobile and plants can't take them out from old leaves.
Other possibility is the plant is shaded and needs more light, hence the slow growth. Not all echinodoruses are low light lovers.
 
sciencefiction said:
It could be. Do you have a picture of the plant in question maybe? Even with phosphate, old leaves should show some sort of damage like chlorosis/necrosis. If old leaves are ok and healthy, then you've got a micro nutrient deficiency. It only manifests in no growth or new growth showing some sort of damage depending on the type of micronutrient, as micro nutrients are not mobile and plants can't take them out from old leaves.
Other possibility is the plant is shaded and needs more light, hence the slow growth. Not all echinodoruses are low light lovers.
Click to expand...
Hi SF,

I will try to sort out a picture.

There is no sign of necrosis or chlorosis on any of the leaves.

The likelihood of a micronutrient deficiency is very low as I dose every couple of days with the full complement of micronutrients. I use Tropica Premium and Specialised Fertilizer alternately. As I also mentioned, I have a JBL Kugeln fertilizer ball inserted in the substrate immediately at the base of the Sword. JBL Kugeln provides micronutrients (+ potassium).

The Sword is receiving plenty of light according to my seneye reef monitor. I measured between 45 and 70 PAR at various positions up and down the plant.

JPC
 
Thanks for the clarification John. It's easy to rule out nutrient deficiency as one can double dose micros for a week or two or dose excess NPK and see if any improvement. If not, it's something else. Flow and distribution is a possibility if co2 is not reaching that part of the tank regularly slowing its growth since there aren't any nutrient deficiency signs that you see. How are the plants surrounding the echinodorus doing? In a high tech you should see impovement in less than a week, possibly days once you sort out the cause.
 
Hi folks,

It's still a mystery to me why the other plants are all growing so well but the E. bleheri is struggling. If it's not allelopathy (and from what I've now read, it probably isn't), then perhaps the other plants are simply outcompeting the E. bleheri for macronutrients. I'm pretty sure it's a macronutrient problem because, as I said previously, the E. bleheri has a JBL Kugeln inserted at its roots. This provides micronutrients only.

Although the E. bleheri is somewhat in the shadow of the filter flow, there is good water flow throughout the tank. The water column is 110 litres and the filter is shifting 800 litres per hour. OK, it falls a little short of the 10x rule of thumb but it's still pretty good. If it is the case that the other plants are outcompeting the E. bleheri, then that would appear to be a good case for macronutrient supplementation in the substrate.

JPC
 
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