[dwalstad]

An Italian hobbyist started a nice thread 'Moving from CO2 to Non-CO2' on Dec 7, 2022. Finally had time to respond.

I need some advise on how to convert my aquarium from CO2 injected to a low tech tank.
First step I sold my CO2 injection system to a friend, big step !
Then I changed the lighting time including a siesta of 4 hours, so 5 hours in the morning + siesta + 6 hours in the afternoon. This allowed me to recover some CO2 , confirmed by the pH meter going down about 0.4 during the siesta.
Anyway plants are not growing so well and my doubt is the substrate.

You mentioned that your Hygrophila polysperma is not growing. I never could get this supposedly easy plant to grow.
Attached is my list of Easy Plants. They are the ones that I have now. The ones I've neglected and abused but keep hanging on over the years.
Some high-tech experts (always use CO2 injection) have commented that the plants I have in my tanks are quite different from those that they and other high techies have. Whatever, the truth is, this list will give people some ideas of a starting place.
Many folks think soil is the magic bullet, but let's not forget about the plants!

 

[mistergreen]

I would add Staurogyne repens, a slow-growing foreground stem plant.

 

[dwalstad]

I tried some Staurogyne 'Porto Velho' that died out on me back in 2007. Could be just me, cuz I didn't take care of it. Maybe the S. repens is better?
The only other plant I really want to try is Nymphaea micrantha. Christel Kasselmann recommended it in an Aquatic Gardener (vol 20, #4) article about back in 2007. Smaller version of Red Tiger Lotus. But I see it is expensive and still not readily available. Anyway, inspired by Johnwesley I'm nursing my Red Tiger Lotus back to health with some TLC. (I moved its pot to back of a tank where it is now getting some sun. It is starting to look pretty good. So I'm thinking I need to take care of what I have. No FOMO!

 

[Michael]

It would be great if this thread became a data base of plants for Walstad aquaria! Especially if we keep in mind that not all easy plants are easy for everyone all the time because of water chemistry and other different conditions. For example I find Hygrophila polysperma to be very easy (too easy?) in relatively new Walstad tanks with their higher levels of CO2 and nutrients. But as the tank ages H. polysperma becomes difficult to maintain. H. corymbosa 'Angustifolia' is much easier to keep long term.

For more easy plants, I would nominate two more Cryptocoryne: C. willisii and C. nurii 'Rosen Maiden'. For some reason the other C. nurii cultivars do not thrive for me.

Diana, I had Nymphaea micrantha 'Gerflect' for a long time and it was easy to grow as long as I gave it a little extra fertility in the soil. If you let it develop floating leaves it is ridiculously easy to propagate. It is vivparous with new plants forming where the petiole meets the leaf blade. Stupidly I let mine deterioate thinking that I could always get more. Now I can't find it anywhere.

 

[mistergreen]

S. Repens are the short stems in the front left. They came from a co2 tank Into this dirt tank and growing slowly.

 

[dwalstad]

It would be great if this thread became a data base of plants for Walstad aquaria! Especially if we keep in mind that not all easy plants are easy for everyone all the time because of water chemistry and other different conditions. For example I find Hygrophila polysperma to be very easy (too easy?) in relatively new Walstad tanks with their higher levels of CO2 and nutrients. But as the tank ages H. polysperma becomes difficult to maintain. H. corymbosa 'Angustifolia' is much easier to keep long term.

For more easy plants, I would nominate two more Cryptocoryne: C. willisii and C. nurii 'Rosen Maiden'. For some reason the other C. nurii cultivars do not thrive for me.

Diana, I had Nymphaea micrantha 'Gerflect' for a long time and it was easy to grow as long as I gave it a little extra fertility in the soil. If you let it develop floating leaves it is ridiculously easy to propagate. It is vivparous with new plants forming where the petiole meets the leaf blade. Stupidly I let mine deteriorate thinking that I could always get more. Now I can't find it anywhere.

Terrific information! Great idea about having this as a thread devoted to plants for Low-tech tanks. One reason I started this thread is that at my aquarium club's last auction, when plants were up for bid, someone in crowd kept yelling, "And doesn't need CO2!"

Also, the nuances about H. polysperma are right on. Everyone says it's an invasive weed, but it didn't last long in my tanks.

I hesitated to start a thread like this because I didn't want to get a "pile on" of confusing information. It is so easy for a plant to do well when the soil is first submerged. And then whether you actually take care of the plant (e.g., Michael's experience with N. micrantha) can introduce other confounds and even more confusion.

Another story: When I started my guppy breeding tanks, I transitioned to Val, Sag, Bacopa, Hornwort, floating plants and pretty much neglected my Crypts. I just wanted industrial water purifiers. But a year later, I noticed that I had a tiny baby plant of brown C. wendtii and a tiny C. blassi (balansae?) still surviving in pots with Val. I recalled how nice these two Crypts had done for me over the years. And they are attractive. So I put each baby in its own pot. They've done well and now I have pots of thriving plant colonies of both species in several tanks.

So this new and very specific information on plants doing well over time is terrific. I will add Michael's suggestion to my list. And I might give Staurogyne repens another chance some day!

 

[johnwesley0]

It's been nearly two years since I purchased my hardy lily (nymphaea). It's a much more delicate plant than the RTL and grows from a tuber. It was 15 months before it finally detached itself and became firmly rooted in the substrate. I like that it maintains a good balance between submerged and emergent leaves.

 

[mistergreen]

I would add any Hydrocotyle.

 

[Michael]

I love Hydrocotyle tripartita but it doesn't love me.

 

[mistergreen]

I love Hydrocotyle tripartita but it doesn't love me.

Interesting. I noticed if they don’t get enough light, they die back.

oh, I want to add a plant.
Crypt. parva. A very slow grower so buy lots.

 

[PlentyCoup]

These all might be too early to tell since i have only recently achieved success with planted tanks but these plants have so far survived every mistake i have made.

I would second hydrocotyle tripartita as well, i thought is was gonner in my Native tank but its really taking off.

For crypts i have to add C. hudoroi it is beautiful almost black in color and growing wonderfully for me.
Also C. green gecko, great patterning. This might be too early to tell but so far all 6 of my c. spiralis "Tiger" are taking off.
C. Usteriana is also great. Upright habit, really nice bright almost lime greem hammered leaves.
I have also wanted to get nurii rosen maiden but havent been able to yet. I do however have nurii "phang mutated" which is in my first betta tank almost two years old now. Its suffering a bit right now but that i think is more to do with how over grown the rotala sp. Caterpillar is.

Rotala H'ra and caterpillar are both wonderful. H'ra has the better color and a slightly more..... behaved growth habit. Caterpiller grows like weed. Both however have the wonderful habit of not really losing their bottom leaves and of sending up new shoots from the very base of the plant. I could not get rotala sp. colorata to grow at all.

This plant must go on the list Persicaria sp. Kawagoeanum. The color is stunning the growth habit is insane, great branching but only suitable for larger tanks love this plant.

Also i cant believe this but alternanthera reinckii variegated. The color is wonderful and so far it has survived every blunder in my native tank. The red color has not faded or changed at all since the tank was set up in October.
I am also tempted to add AR mini to the list. I have 5 stems in my new betta vase and so far they are taking off.

Also Lindernia sp india which was a feebee in one of my orders. It is supposed to be a hard to grow plant but it too has grown like a weed in my native tank. It reminds me a lot of a bacopa. Very tall, small round leaves and good branching.

 

[mistergreen]

I think I had a few stems of Lindernia. It grew for a bit and then died off.

 

[Oslo]

Of the plants I have, Nymphoides hydrophylla "taiwan", Hygrophila polysperma, and Vallisneria spiralis grows best/fastest in my newly established Walstad tanks.

 

[dwalstad]

Of the plants I have, Nymphoides hydrophylla "taiwan", Hygrophila polysperma, and Vallisneria spiralis grows best/fastest in my newly established Walstad tanks.

"Newly established..." Be prepared for changes as time goes by, say two years from now.

 

[rafael.nicolaidis]

I've been keeping Mayaca fluviatilis and various Eleocharis in a non-CO2 enriched tank by the window for one year. 0-1 KH, 5.8 pH, 6 °GH, aquasoil.

Also, in a two year old tank, same water parameters but artificial light with siesta timing, Helanthium tenellum.

 

[PlentyCoup]

I guess i should reframe my list based on age of my tanks.
In my soon to be 2 year old betta tank its rotala h'ra and caterpillar, c. Phang mutated and parva, guppy grass and an extremely resilient piece of star grass as well as now unknown buce.
In that same tank i have lost bacopa, it grow well for awhile and then just disappeared, along with c. Wendtii red, echinodorus keliner prinz and a ludwigia cant remember the variety.

In my soon to be 4 month old 36 gallon its c. Hudoroi, green gecko, ustetiana, Persicaria sp. Kawagoeanum, Lindernia sp india, AR variegated, anubias coffeefolia.

Plants i have lost in that same time frame, rotala sp. Colorata, hygro pinnatifida, micro sword, echinodorus major.

Plants have not written off but are not doing great. Leopard val, echinodorus marble queen, rose, and hygro compacta also c. Tropica and c. Costata.

I am sure this can all change but i am pretty confidant about the plants in older betta tank and hopeful that those listed in my 36 gal continue to preform well.

 

[maico996]

S. Repens did well for me for a while, but as the taller plants got taller and the floaters went crazy, they were receiving less and less light. They slowly stopped growing and eventually disappeared. I think I have one or two stems left. My conclusion is that they need a lot of light, more so than I'm willing to give them. Without CO2 and lots of light, they haven't worked in my tank.

 

[mistergreen]

Yes, S. repens need light. It won't do well if the lights are blocked. I think this is true with most foreground plants.

 

[dwalstad]

Yes, S. repens need light. It won't do well if the lights are blocked. I think this is true with most foreground plants.

Yes, poor things are at the bottom of the tank where light has dropped off considerably due to passage through water.

 

[mistergreen]

Yeah, I killed off almost all my C. Parva when I changed to a less intense light. Now they sit emmersed in a plastic cup.