Choosing Aquarium Plants For Soft And/Or Hard Water

jaypeecee

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Hi Folks,

I very recently got myself a copy of Diana Walstad's book, Ecology of the Planted Aquarium. In this book, Diana Walstad discusses plants that are suitable for soft vs hard water. Plant requirements on plant labels may specify lighting, temperature and CO2 requirements. But, they don't appear to say if a plant is suitable for soft and/or hard water. Tied in with water hardness is acidity/alkalinity. My understanding is that soft water in natural habitats is usually acidic (pH less than 7.0) and hard water in natural habitats is alkaline (pH greater than 7.0).

Where can I get a list of aquarium plants that includes recommended water hardness?

JPC
 
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dw1305

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Hi all,
Where can I get a list of aquarium plants that includes recommended water hardness?
My guess woul be that most of the plants that are commonly sold by non-specialist shops (<"Tropica Easy Section">?) etc. are selected partially because they aren't too bothered about water hardness.

I think Diana Walstad lists plants that can use bicarbonate as a carbon source? In that case they should all do well in harder water, if they can't they are more likely to struggle.

There are a few threads on the site. Have a look at <"Windowsill nature"> & <"Windowsill Nature pt 2."> for plants that do well in hard water.

cheers Darrel
 

jaypeecee

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I think Diana Walstad lists plants that can use bicarbonate as a carbon source? In that case they should all do well in harder water, if they can't they are more likely to struggle.

Hi Darrel,

Yes, Diana Walstad does indeed list a selection of plants that can, and can't, use bicarbonates. It would appear that some plants prefer softwater, acidic conditions whilst others prefer hardwater, alkaline conditions. If that's the case, I want to ensure that I choose my fish and plants accordingly. As I'm starting afresh with this tank and I'll be using remineralized RO water, I can tailor my water properties to suit. It seems that some plants can use bicarbonates as a source of carbon instead of being wholly dependent on CO2. The following makes it clearer what's going on. I know you've referenced this several times but I include it here for convenience.

CO2_HCO3_CO3_pH.jpg

This is all very interesting stuff.

JPC
 

dw1305

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Hi all,
As I'm starting afresh with this tank and I'll be using remineralized RO water, I can tailor my water properties to suit.
I'd just choose some plants you like the look of. The chances are that the majority of them will be fine in hard, or soft, water.

If there are plants you particularly want? Have a look and see if there is any reference to special requirements in regards of pH or hardness.

<"If there isn't?"> I'd try about <"4dGH/dKH">.

As an example I've found that my rainwater (~120 microS and ~4dKH) is too soft for Vallisneria, but it grows well in our tap water (~18dKH), even with a low nutrient addition, so this looks definitely like a hardness requirement.

We also have a lot of <"Rotala threads"> where the plants are showing clear signs of iron induced chlorosis, and I would take that as a pretty good indication that Rotala rotundifolia is much happier in softer water.

cheers Darrel
 

jaypeecee

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Hi Darrel,

If there are plants you particularly want? Have a look and see if there is any reference to special requirements in regards of pH or hardness.

But, where can I find this pH and hardness information? If sources don't mention pH or hardness, I can't automatically assume that pH and/or hardness are unimportant. Been there, done that, got the 'T' shirt.

<"If there isn't?"> I'd try about <"4dGH/dKH">.

I run my tanks at 4dKH or slightly above this figure. 4dGH is very soft water but it's a possibility.

As an example I've found that my rainwater (~120 microS and ~4dKH) is too soft for Vallisneria, but it grows well in our tap water (~18dKH), even with a low nutrient addition, so this looks definitely like a hardness requirement.

Yes, V. spiralis is a plant on which Diana Walstad carried out an experiment. This plant was shown to distinctly dislike acidic soft water!

We also have a lot of <"Rotala threads"> where the plants are showing clear signs of iron induced chlorosis, and I would take that as a pretty good indication that Rotala rotundifolia is much happier in softer water.

Thanks for the link, which I'll check out a bit later. That sounds like the kind of information that I am trying to find. I still consider myself a beginner with aquatic plants - despite having been growing them with some success over the last few years. I can't understand why it's so difficult to obtain all the information needed to get off to a good start. I have had many failures with aquatic plants but it's not through lack of trying.

JPC
 

dw1305

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Hi all,
A lot of members have hard water. @ian_m, @Zeus. @Tim Harrison etc. may be able to make suggestions? I've always used rainwater in the tanks, so I'm not the best person to ask.

I use the "three strikes and you're out" rule for plants both for the garden and aquarium, they have to cope with what their given. If I really like a plant, and I think it should grow, it gets a maximum of three chances. <"Romneya coulteri"> is the one that really annoys me. Just up the road it grows with magnificent abandon, even coming up through the pavement, in our garden it just dies.

That is partially why I have such a limited range of plants, the ones I still own have to have grown reliably with a certain amount of benign neglect.

cheers Darrel
 
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Zeus.

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I use the "three strikes and you're out" rule for plants both for the garden and aquarium, they have to cope with what their given. If I really like a plant, and I think it should grow, it gets a maximum of three chances.

I copy Darrel, if I like the plant try it...... some dont even get two chances :lol:
 

Tim Harrison

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I'm the same, as both Darrel and Karl. I pretty much choose plants to suit the conditions in my garden and aquarium. If they're determined not to grow I usually give up after a couple or three attempts,

As far as soft or hard water plants go, most plants couldn't care less. Maybe some will be easier to grow in soft water and others will perhaps look a bit better. Conversely, some plants may do better in hard water because they can synthesise carbon from bicarbonates, plants like vallis, crypts, anubias and some mosses etc.

At the end of the day though if I really like a plant I usually ignore other folks/experts opinions and try it anyway. Half the time they're just plain wrong or have confused cause and effect. I've lost count of the times plants have thrived or died when and where they "shouldn't" have.
 

Zeus.

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Take Bolbitis Heuelotii

Bolbitis comes from West Africa, a fern with beautiful, transparent green leaves, 15-40 cm tall and wide. When planting, do not cover the rhizome because it will rot, and it is best to plant Bolbitis heudelotii on a root or stone. Keep the plant in position with fishing line until it has gained a hold. Easy to propagate by splitting the horizontal rhizome.
Supply of CO2 will considerably enhance the growth, which is only optimal in soft, slightly acidic water.

So popped some in my little crowded tank you can just make it out among the Anubis
upload_2020-3-28_20-49-15.png


Poor light poor CO2 forget to add ferts most of time, yet its growing fine, infact it looks better than in my main tank :rolleyes:
 

sparkyweasel

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I usually ignore other folks/experts opinions and try it anyway. Half the time they're just plain wrong or have confused cause and effect. I've lost count of the times plants have thrived or died when and where they "shouldn't" have.
That's a good plan. The important thing is; don't let your plants and fish read the books. :)
 
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As you guys know I have only low energy systems, plants like bolbitis also grow well for me when they shouldn’t - as do bulb plants such as aponogeton crispus and nymphaea lotus which supposedly need medium light. There are plants I’ve not been successful with though that I probably ‘should’ be able to grow.. cardamine lyrata grows but never lasts very long and rotala sp. have never really done well either.
 

Onoma1

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I first saw Staurogyne Repens in one of the Green Machine videos and most see it as an easy plant, however, it just doesn't seem to grow in my tanks. I have always put this down to it not thriving in soft water.
 
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I believe it takes a long time to get going and to adapt to submerged growth... I don’t think I have it long enough when I tried it...
 

Conort2

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I first saw Staurogyne Repens in one of the Green Machine videos and most see it as an easy plant, however, it just doesn't seem to grow in my tanks. I have always put this down to it not thriving in soft water.
It does seem to take ages to get going, I’ve had a tissue culture version of this for months now. It now only really seems to have started to get going. It sat there for months doing hardly nothing except for die back. Saying that it’s still very slow compared to other plants in the tank.

One plant that is supposedly easy but I can only grow with co2 is java fern! The stuff is supposed to be bullet proof yet I can only grow it with additional co2. Low tech it does absolutely nothing and fades away.

cheers

Conor
 

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