Amazon Sword Cant Get To Grow

[johnw]

I have about 140 litre tank, I used to be able to grow this plant It used to spread over the bottom of the tank and its leaves reached to the water surface, then I must have changed something in the setup because they started dying off and now I don't have any! I know it wasn't the lighting I did not alter that the water temperature was changed but I put it at about 28 C. The substrate was a black sand then a layer of gravel on top. I've tried with a heating cable in the sand and without. I have a plecostomus in the tank. The water pH is maintained as close as possible to 7.0.
Any suggestions of what I'm doing wrong.

 

[RadaR]

Do they leaves fall apart and get holey?
Do they lose their colour and struggle to grow?

If you havn't changed anything then it sounds like lack of nutrients to me.
Before anyone says "amazon swords are heavy root feeders", let me clarify that this isn't true. Their large root network is primarly to hold them in place. Amazon swords will take in nutrients through their leaves from the water column like nobodies business.

The algae link in my sig takes you to a website that will also have a guide to plant deficiencies.

 

[johnw]

Maybe it's a nutritional problem as suggested? Can I have some thoughts on sand for substrate do they like small particle size for rooting? Gravel? I did try a liquid plant feed did not seem to help? Concerned that adding plant feed will cause an increase in algae.
My tank is bear of plants (any plants) at the moment and I'm concerned that it's stressing the pleco as it has no cover.

Thoughts on under-gravel heating - good or bad? I really don't know.

By the way I'm in the county East Sussex, If anyone has spare plants please let me know I can travel at weekends can offer guppies.

 

[SO19Firearms]

Do they leaves fall apart and get holey?
Do they lose their colour and struggle to grow?

This really.

But just to start guessing at stuff - It sounds like too much light against not enough ferts/CO2.
Low light, Plant heavy, good nutrient like a home made one, 1/3E.I., TPN or TNClite and not so many water changes.
or High light, Plant heavy, CO2, good nutrient like a home made one, E.I,, TPN+ or TNC Complete and plenty of water changes.

Don't waste money on heater cables - They're snakes. (Snake oil if they were liquid.....)

As for root feeders, I'm not sure that adding good (NPK+Trace) substrate tablets isn't such a bad idea if you're scared of dosing the water column to begin with....

 

[TwoTankAmin]

Before anyone says "amazon swords are heavy root feeders", let me clarify that this isn't true.

Why do roots exist?

by Elizabeth Worobel <eworobe-at-cc.UManitoba.CA>
Date: Tue, 18 Jun 1996
Several different types of experiments have been carried out in attempts
to answer this question. The first type, first tried almost 100 years
ago, asked the question "Do rooted aquatic plants grow better with a
nutrient rich substrate or with a sand substrate and a nutrient rich
water column." The data clearly indicated that rooted aquatic plants,
though they will grow on sand with nutrients supplied in the water
column, grew far better with nutrients supplied through a rich substrate.
These experiments have been repeated many, many times since with many
different types of rooted aquatic plants and the data consistently show
that plants grown on substrates outgrow those grown on sand with
nutrients supplied through the water column.
The second question was "Which nutrients can be supplied exclusively from
the sediment and which must be supplied via the water column." The data
clearly indicate that P and N can be supplied from the sediment and that
S and micronutrients may also be supplied exclusively from the sediment
(the data for N and P is much more extensive). The only nutrients which
are needed in the water column are Mg, K, Ca and of course CO2. These
consistent for several different types of rooted macrophytes on many
different types of sediments.
The third question was "Which nutrients actually are supplied via the
roots from the sediment." This typ of experiment is much more difficult
to carry out but the evidence indicates that N and P are obtained by
rooted aquatic plants from the sediment, even when readily available in
the water column (this includes genera such as Elodea and Myriophyllum
which have small root:shoot ratios).
The fourth question is "Which nutrients can be supplied exclusively from
the water column." As far as I know this remains unanswered as it is
extremely difficult to manipulate the nutrient content of saturated soils.

From thekrib.com

Roots versus Shoots in Nutrient Uptake by Aquatic Macrophytes in Flowing Waters
P. A. Chambers, E. E. Prepas, M. L. Bothwell, H. R. Hamilton

Published on the web 11 April 2011.

Canadian Journal of Fisheries and Aquatic Sciences, 1989, 463) 435-439, 10.1139/f89-058


Abstract
Transplant experiments conducted in the South Saskatchewan River, Saskatchewan, Canada showed that the aquatic macrophyte, Potamogeton crispus, obtained most of its nutrients through the roots. When plants were grown in buckets containing high (602 μg∙g[sup]−1[/sup] total phosphorus; 712 μg∙g[sup]−1[/sup] total organic nitrogen) or low (258 μg∙g[sup]−1[/sup] total phosphorus; 109 μg∙g[sup]−1[/sup] total organic nitrogen) nutrient sediments and exposed to high (75 μg∙L[sup]−1[/sup] soluble reactive phosphorus (SRP); 530 μg∙L[sup]−1[/sup] total dissolved nitrogen (TDN), or low (10 μg∙L[sup]−1[/sup] SRP; 323 μg∙L[sup]−1[/sup] TDN) nutrient concentrations in the open water, biomass, shoot density and tissue nutrient concentrations were largely determined by sediment type, rather than open water chemistry. These results indicate that the roots are an important site of nutrient uptake for aquatic macrophytes in flowing waters.

From http/www.nrcresearchpress.com/doi/abs/10.1139/f89-058

Rather than my pasting any more you can go to Google Scholar and do a search for "aquatic plants + nutrient uptake"

 

[ian]

I'm sure wev'e had this discussion before haven't we? lol

There is no such thing as a heavy root feeder. Plants will take from the root, however they will also take from the column just as much as they will take from the root. They are both as important as each other. Remember the water column extends into the substrate. With correct column dosing swords don't need a rich substrate.

 

[SO19Firearms]

6 of one, half a dozen of another I reckon really. If you're growing any of these emmersed it pays to foliar feed for instance.....

There is no such thing as a heavy root feeder.

I'd pretty much stand-by that.

 

[TwoTankAmin]

Yes and we will continue to have the same discussion until somebody can produce scientifically supported evidence to the contrary. I can cite research study after research study relating to this topic and in support of the view that a number of aquatic plants are root feeders by preference. All I see from the other camp are unsupported statements that there is no such thing as heavy root feeders re aquatic plants.

It can be possible in a more high tech tank where one is running pressurized co2, has high light levels and nutrients are being dosed anywhere from twice a week to daily for plants which normally rely primarily on root feeding to get a lot of what they need from the water column. Basically, to get a plant which would normally feed more via its roots than its leaves to switch over to mostly leaf intake, you have to force feed the leaves with very high nutrient levels, higher than what is available via the roots. For the average tank this simply wont happen and the plants should be fed via their roots.

My experience with swords and having them decide to throw up runners and to make babies and flowers is that this happens most often in close proximity with my having done a root feeding.

When folks say there is no such thing as a heavy root feeder (and for me this means a plant which normally takes more nurtients via the roots than the leaves), why on earth would there be so much discussion of planted tank substrates. Why is there laterite or fluorite, why is their ADA soil, etc. etc. etc.

 

[ian]

planted substrate don't tend to contain the amount of NPK that we would dose into the water column (which a sword relies on), planted substrates also go above and beyond just 'root feeding plants'. They help on C02 aspects in the tank, micro dosing via leeching etc etc. Its not just for feeding roots that we would use planted substrates. I'm sure in one of our other discussions that there was some evidence produced that was done by Tom Barr, which you pushed aside, claiming that you'd had discussions and arguments with Tom in the past. Now Toms evidence stands better than the evidence you have produced. Your evidence is 15 years old. This for me would be 'old hat'. The second piece is just rubbish, to quote the article 'we put the plants in buckets', that's where i stopped reading. It's fine looking through google scholar but most of these are research articles aren't even peer reviewed.

If you read back, i didn't state that Swords didn't feed via the root, they do. The just are not 'heavy' root feeders. With adequate water column dosing they will take from the water column. The roots of a sword are big...for the reason they get flooded and the sword need to be able to hold onto the ground or else it would be washed away and probably die. They are found in fast flowing streams.

just a bit of anecdotal evidence but i have seen numerous swords grown in just either micro substrates or inert, with C02 and EI and there has been no ill health to the sword.

to quote Tom

as A Hill suggests, it's easy once you add sediment ferts, but it's not something that applies to one group of plant. "Plants are opportunist". Researchers do not debate this subject much with good reason. So add to both locations, this hedges your method against nutrient error/limitations. Roots, tubers and rhizomes provide storage for dry drought conditions, low light and other adverse aquatic conditions.