You could float the hygro. It should still grow fine since it's a leaf feeder. If it still dies, that rules out substrate poisoning (unless it's something getting into the water itself from the substrate). Hygro shows co2 deficiencies with holes/leaf loss. But usually you will still see new growth happening. It's not a hard plant to keep, but sucks up nutrients fast. I transplant cuttings from my co2 to my non-co2 tanks with just a slack in growth for a few days to a week until they get adapted again, at which point they continue to grow, albeit slower than in the co2 tank. If hygro dies on you, there's got to be some nutrient lacking there that the slow growing crypts don't have as much demand for and/or are getting it from the substrate, not the water column.

Thanks, Ceg,


I have monitored the nitrate and phosphate levels in this tank since it was set up. There have been ups and downs, but for at least the last 2 years they have been within a normal range. I dose Flourish monthly, and I added some Equilibrium a month ago just in case.



I understand that. But high light and inadequate carbon usually result in stringy growth in stem plants until they die off. The hygros just withered in a few days (if plants can wither underwater) . Note that the root plants also died in a few days.

All of the plants came from non-Co2 injected environments.


I measure macros and hardness with test kits. I validated the phosphate kit; I've used the nitrate kit for years with satisfactory results in all environments.



I know that there are many variables. I am just reporting what I observe. I think normally, given the symptom of rapid death of new plants in just a few days, some would suggest a poisoning of some kind.

BTW, 2.5 days ago I added a tbsp. of duckweed to that tank. It covered about 1/5 of the surface, loosely spaced. Duckweed grow great for me in other tanks. This morning it was all gone, except for about 10 pieces. None of those plantlets had any roots!!!

Thanks again.

Bill

Tom posted, in part

I don't know to what extent you were commenting in the hygro - crypt situation, but isn't it likely that a plant that gets it's nutrients from the water column, like hygro, would have no trouble competing with a substrate-feeder, like crypt, no matter how long it had been established? (Unless the crypt was putting out allelopathic poisons, of course.)

Bill

I posted earlier (after your post) that I added about a tbsp. of duckweed to the tank in question and it died in less than 3 days, except for about 10 plantlets who are hanging on without roots. I'm sure they will be gone tomorrow.

Instead of looking at this from a not-enough-nutrients angle, why not consider a poison-in-the-water possibility?

Bill

Just a minor quibble: plants with extensive root systems are not necessarily "root feeders", just as plants with few roots are necessarily "water feeders". Roots serve the purpose of anchoring plants in moving water, as well as feeding then, so those plants with roots may or may not depend on their roots for food.

Now, my two cents worth:
It seems obvious that something changed in your tank, and changed for the worse. Even a shortage of nitrates shouldn't cause the rapid decline you reported. In fact I doubt that any shortage would cause that.

I also doubt that allelopathy is the problem. So, I'm left wondering if something like chlorine, or chloramines could be involved. Or copper, except that would kill off the fish before bothering the plants. Perhaps a detergent residue? If you had the capability of doing a thorough water quality analysis of your tap water that would be my first suggestion. If not, then RO/DI water, reconstituted properly, would be my next suggestion.

On second thought, take my advice free! Keep the two cents.

You could try planting another crypt in there. The way you are describing it, it does sound like something major is amiss, not just a simple deficiency. If I had to guess right now, I would say that either there is something in the water, or too much of something in the water, that the crypts have adapted to, but other plants are having trouble adapting to. If it's allelopathic compounds from the crypts, another crypt should live fine, or at least as well as a crypt will do when transplanted, which might be hard to qualify.

Fast growers like hygrophila polysperma (you can't get much faster than that) will show deficiencies much sooner than slow growers like crypts. Their faster rate of growth means that they have a very high demand on nutrients, which shows itself very quickly if any nutrients are at semi-low levels; whereas a crypt can live under very low levels of nutrients, sometimes indefinitely, without any visible problems, especially if nutrients are available in the substrate and it has an established root system to get them already. I think that's the big difference between your crypts and the plants you are adding, besides some being fast growers, they are relying on the water column heavily for their nutrients, plus the stress of changing conditions etc. is not in their favor; whereas the crypts do not need to rely on the water column at this point, and probably have very extensive roots. The anubias are also extremely slow growers. In my co2 injected tank, I'm lucky if I see a leaf a month or every two months.

Hoppy, most of the water in the troubled aquarium has come from my 150 foot deep well, which I have been drinking and using in aquariums for decades. It has been augmented with water from a brook that flows from a swamp, cool, acid water that supports a good population of native brook trout. I've been using that for a long time, too.

I do have some copper pipe in my house, but the fish and plants in other tanks are thriving, and those tanks use the same water.

Looking back at my aquarium log, the only things that have been added to the aquarium in the last 18 months has been KNO3 (a little every other month), Fleet Enema (rarely), Equilibrium (once), Flourish (3 or 4 times), and Excel (3 or 4 times.) The last Excel dose was 5 weeks before the vals were planted.

Carissa, your idea of adding a crypt from another tank is a good one, but the crypts in the tank in question continue to produce new plants, and I'd think that they would not inherit any "immunity" to water conditions that the parent had. I'm not sure, though.

The poor hygros did not live long enough to show any signs of nutrient defficiency.

Here's a link to an article by Ole Pederson of Tropica on allelopathy in aquatic plants. He cites a number of examples, none, unfortunately, involving crypts. Tropica

Bill

The point I made was more about established vs new introduction.
Adding a plant to a dense bed of weeds vs adding it an open area..........where would you predict it might do better?

To be fair, take one of each plant type and place them in an open area.
Then see.

Regards,
Tom Barr

Well, there was something missing then.
Anyway, the article Ole wrote pretty much states it's never been demonstrated in any natural system.

I linked it some time ago in the articles, it was his refute of Diana Walstad's speculation of allelopathy. I took a different approach in my refute.

Still, neither he or I, nor any researcher I know would suggest that it plays a strong role in any system studied to date.

I've grown Crypts for decades and some of the flowers are on the Crypt's pages.
I've done hormone treatments like Dr Kane on them. Most of the results/data suggest what the research suggest.

Perhaps one day they will find it in a natural system or perhaps an aquarium, I was asked that some years ago at the AGA, I could not do anything other than speculate and guess and the guess was wrong and there was not any interaction after I did the test later.

The test are rather easy once you have a suspect.
But choosing your plants is the hard part.
All you need is to have the plants doing well together in another tank as an example to falsify the hypothesis that they have a chemical interaction.
Then add activated carbon etc as a control as well.

You have to be careful in your speculations since it might just be horticulture issues rather than biological relationships like allelopathy or algae prefer this or that.

If you have poor control as an aquarist, or you think you have control but really do not........then you are in trouble and cannot correct the issue easily. That will lead you to think everyone is crazy and you are right.

You have to trust folks that are growing the plants well together.
They have no reason to lie. Then you go about figuring out why they have no issue but you do.

Fairly straight forward process.
But sometimes the folks doing well do not know what they are doing, or assume their parameters are one when they are something quite different(CO2 most commonly- go figure.........)

Regards,
Tom Barr