Underwater Hydroponics

[ShinySideUp]

Many above-ground plants are grown in a water system, i.e. hydroponically, so their roots sit in a flow of nutrient-rich water, could this be possible for aquarium plants? I know there are species of plants that mustn't be placed in the substrate but with a suitable anchoring grid I see little reason why all aquarium plants can't be grown this way. Anyone tried this?

 

[stu40]

sorry, i'm being dense, but i'm not sure i understand the question
Do you mean something like in this thread?

 

[hensonc4098]

I think the OP means that the plant is held part way up the stem in a grid of sorts, and the roots are sitting in nutrient rich flowing water. Therefore they are getting the advantages of unlimited co2 from being out of the water and unlimited nutrients in the water.

With regards to if it can be done in aquatic plants, I see no reason why not. Many of them are grown completely immersed, so the plants can obviously adapt to having their leaves exposed. Not sure though what difference in growth rate you would see though. Would be an interesting experiment

 

[ShinySideUp]

I think the OP means that the plant is held part way up the stem in a grid of sorts, and the roots are sitting in nutrient rich flowing water. Therefore they are getting the advantages of unlimited co2 from being out of the water and unlimited nutrients in the water.

With regards to if it can be done in aquatic plants, I see no reason why not. Many of them are grown completely immersed, so the plants can obviously adapt to having their leaves exposed. Not sure though what difference in growth rate you would see though. Would be an interesting experiment

Almost but not quite. Let's say I have a fully aquatic plant that is 'designed' to grow underwater in the soil/gravel/sand at the bottom of the lake/tank/pond; it is an underwater plant. Now that plant is using it's roots not only to gain nutrient but also to anchor itself so it doesn't get swept away. Similarly, there are above-ground plants -- tomatoes for example -- that also anchor themselves in the ground. However, tomato plants can also be grown hydroponically in that they are mounted in such a way that their roots are not in soil but held in nutrient-rich water. They grow finer, less robust, roots and the plant is held down artificially.

My suggestion is to hold fully-submerged plants in such a way that their roots are not in the substrate but lie in a flow of nutrient-rich water actually in the aquarium. Should this work then the plant will survive as normal but it's root system will also provide habitat for some fish species without growing in the substrate.

If this worked it has the added bonus of being able to vacuum the substrate without disturbing the roots of plants as they are able to be moved, on their anchoring system, out of the way.



Further to your post however, Henson, your suggestion of my idea of underwater hydroponics added to your partial-submersion hydroponics concept is also interesting. In the first instance I shall try my idea, if it works and I have a viable plant with free-flowing roots then it is a small matter to move the plant up the tank so it's upper leaves are exposed to air with it's roots still free in the water.

I'm sure if this was possible it would already have been done but one never knows.

 

[hensonc4098]

Ahh right, I getcha. Interesting. Definitely would make an interesting experiment. Exposing the leaves makes it more of a propagation exercise I suppose, whereas trying to keep them immersed makes maintenance easier - just whip them out for a quick trim and shove it back in again

 

[SO19Firearms]

My suggestion is to hold fully-submerged plants in such a way that their roots are not in the substrate but lie in a flow of nutrient-rich water actually in the aquarium.

I'm not sure I get it - Do you mean just have a normal aquarium, but suspend the plants in the water?
What do you hope to gain from the project?

 

[BigTom]

Pretty much all aquatic plants will absorb nutrients just as happily from the water column through their leaves and stems as through their roots. If you've got a balanced fert dosing regime this should be no problem at all, and is in essence no different from growing plants in an inert substrate like sand or rock wool.

 

[ShinySideUp]

My suggestion is to hold fully-submerged plants in such a way that their roots are not in the substrate but lie in a flow of nutrient-rich water actually in the aquarium.

I'm not sure I get it - Do you mean just have a normal aquarium, but suspend the plants in the water?
What do you hope to gain from the project?

Two things: The convenience of being able to move the plants for substrate cleaning and secondly to provide additional areas for egg-layers to hide their eggs. Oh and one other thing; to see if I can.

 

[SO19Firearms]

Oh and one other thing; to see if I can.

That has to be the best reason. There may be an issue with light and the roots. You'll notice plants like Java fern, Anubius and floating plants have black wirey roots where as "terrestrial" plants have white delicate roots - Whether this has any baring in the final experiment we will see. I'd imagine crypts won't like it, as they don't really like running water at the root zone but it's all worth a try.

 

[ShinySideUp]

Oh and one other thing; to see if I can.

That has to be the best reason. There may be an issue with light and the roots. You'll notice plants like Java fern, Anubius and floating plants have black wirey roots where as "terrestrial" plants have white delicate roots

I do have some floating plants for the first time and it is this that started me off on this idea. The roots of the floaters are long, brown and fine and my diamond tetra's love brushing through them.

 

[BigTom]

If you've got an open top tank then you can easily grow lots of different houseplants with their bare roots in the water. You can create a really dense jungle of roots this way, if that's what you're after.

 

[hensonc4098]

If you've got an open top tank then you can easily grow lots of different houseplants with their bare roots in the water. You can create a really dense jungle of roots this way, if that's what you're after.

How do you balance them so that it's just their roots in the water? And stop it being all soily

 

[SO19Firearms]

How do you balance them so that it's just their roots in the water? And stop it being all soily

You wash the soil off. Google "Hydroculture" to learn more about switching terrestrial roots over to aquatic.
To secure them you can replace the soil with a medium like perlite, rockwool or fired clay - or clip them up with a collar.
Meeting the needs of house plants with tank water might be a bit harder tho.

IMO

 

[BigTom]

Heh yeah, you just wash the soil off the roots. Some plants will take a few weeks to adapt while they grow a different sort of root system suitable for being in water. And there are various ways of supporting them... you can put them in shower caddies filled with hydroton and wait for the roots to grow through, or just balance them behind a bit of hardscape or train them up some branches if they're climbers. Just takes a little bit of ingenuity.

And house plants need just the same nutrients as aquatic plants to grow, but they're a lot easier because they have access to atmospheric CO2.

 

[hensonc4098]

I've seen it done in your journal Tom and it looks really good - it's another one to add to the list to try one day The tanks I have at the moment don't really lend themselves to that sort of thing due to their size and shape, but a square-based tank for extra depth may be in order.

One thing at a time though - I'll set up the 180 first