Help! Hygrophila deficiency, not sure............

Rloiyao

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Hi all,
I am new to the forum and new to aquatic plants.
Got some hygros a month ago and this is the only plant in the tank....... starting to see pin holes, yellowing, browning, turn white and melting from last 2 weeks.
Since then I have been adding excel, potassium and flourish all following the dosage instruction since I got no idea lol. But the plants still do not look ok. Can anyone please help.
excel: everyday. potassium: every 2 days. flourish: every 3 days.
Tank: 80L
Ammonia:0 Nitrite:0 Nitrate:5
I am not sure about the lighting, I think its about 11W led light with the white and blue light. The light is on for 5.5 hours a day.
Ta!
 

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Parablennius

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Regarding your frogbit we can rule out carbon and probably light, given it's place. That leaves ferts. What is your GH? All my plants improved enormously when I upped the GH by 2 deg from the tap by adding Calcium nitrate and Magnesium sulphate in addition to the ferts. Keep tank, and change water at 5GH now. Even reducing ferts hasn't slowed growth. HTH
 

Rloiyao

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Regarding your frogbit we can rule out carbon and probably light, given it's place. That leaves ferts. What is your GH? All my plants improved enormously when I upped the GH by 2 deg from the tap by adding Calcium nitrate and Magnesium sulphate in addition to the ferts. Keep tank, and change water at 5GH now. Even reducing ferts hasn't slowed growth. HTH
Thanks for the reply. Do you know what happen to the frogbits?
My GH is around 12 cause i got some livebearers inside the tank, I use equilibrium to raise GH when doing weekly water change.
 

Parablennius

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All I can say is that in my case raising GH to 5 from 3 helped. I'm no expert but with 12GH that just leaves ferts. I read that frogbit is nitrate hungry. I took Darrel's lead re. "Duckweed index", I use mine as a canary. Maybe more NPK?
 

Simon Cole

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You have a mobile nutrient deficiency. Stop adding Excel - that stuff is dangerous and is used to treat algae. Get yourself a macro-nutrient fertiliser with nitrogen and phosphorous included. Start dosing that as well as a half dose of the flourish, and the potassium, if that is not included with the macro. Change your water 50% every week. Perhaps upgrade your lighting, or up this to 7 hours. Pressurised carbon dioxide would also help.
 

alto

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Stop adding Excel - that stuff is dangerous and is used to treat algae.
An interesting (& worthwhile) read

From sub cellular to community level: Toxicity of glutaraldehyde to several aquatic organisms
Susana P.P. Pereira, Rhaul Oliveira, Sónia Coelho, Carolina Musso, Amadeu M.V.M. Soares, Inês Domingues, António J.A. Nogueira

Excerpt
Interestingly, GA promoted the growth of L.minor at low concentrations (NOEC = 4 mg/l)(Table4).
No references in the literature were discovered displaying evidences of the GA boosting effect in primary producers, however there are available commercial products containing polymerized isomers of GA (polycycloglutaracetal), which are employed in the water as fertilizer of aquatic plants (e.g. Flourish Excel™, in the United States).
The product sheet of Flourish Excel describes the CO2 rising from GA degradation (process previously described in detail by Leung(2001b)) as an additional source of carbon that might be used by L. minor.
Excerpt
Studies of the GA effects to fish species reported a wide range of lethal values (Table 1).
A good agreement of LC50 values for D. rerio adults was found between this study and OECD SIDS (1998), 5.3 and 5.8 mg/l, respectively. Other fish species, namely Pimephales promelas, Oncorhynchusmykiss ,and Oncorhynchuskisutch, show a similar sensitivity to D. rerio whereas Cyprinodon variegates and Lepomis macrochirus seem to be about 4 to 5 times more resistant than D. rerio
Conclusion
GA is moderately toxic to aquatic organisms with toxicity values ranging from 3.6 mg/l to 31.3 mg/l for the tested species. Moreover, GA had a similar biocide effect on organisms, which appeared to be independent of the trophic level, although microcrustaceans showed to be slightly more sensitive. Several sublethal endpoints were measured in D. rerio embryos and adults. For embryos, malformations and hatching delay can be highlighted as sensitive endpoints, while for adults the CAT activity showed to be the most sensitive biomarker to GA exposure. Furthermore, the sub lethal effects in D. rerio and other organisms should be further investigated as important information about population fitness can be inferred (e.g. the decreaseof root size observed in L. minor ).
Considering the wide-ranging of effects varying with the life stage and organism tested and the relatively low HC5 value of 0.6mg/l, mesocosm and chronic toxicity tests seem to be the next step in direction to more realistic scenarios of GA risk assessment in aquatic ecosystems
 

alto

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Aerobic and anaerobic metabolism of glutaraldehyde in a river water-sediment system.

Leung, HW

Abstract
Material balance studies of glutaraldehyde in a river water-sediment system demonstrate that glutaraldehyde preferred to remain in the water phase. Glutaraldehyde was metabolized rapidly under both aerobic and anaerobic conditions. The pseudo-first-order half-life of catabolism, based on the loss of glutaraldehyde from the water phase, was 10.6 h aerobically and 7.7 h anaerobically. In contrast, under sterile conditions at pH 5 or 7, no appreciable degradation of glutaraldehyde was observed over a 31-day period. At pH 9, about 30% of the glutaraldehyde degraded over the same period. The major degradate was identified as 3-formyl-6-hydroxy-2-cyclohexene-1-propanal, a cyclicized dimer of glutaraldehyde. The extrapolated half-life of abiotic degradation was 508 days at pH 5, 102 days at pH 7, and 46 days at pH 9. Under aerobic conditions, glutaraldehyde was first biotransformed into the intermediate glutaric acid, which then underwent further metabolism ultimately to carbon dioxide. Metabolism of glutaraldehyde under anaerobic conditions did not proceed ultimately to methane, but terminated with the formation of 1,5-pentanediol via 5-hydroxypentanal as an intermediate.
 

alto

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Got some hygros a month ago and this is the only plant in the tank
Any further information on plant species or source?
Looks as if the old emerse culture leafs are dying
Are you seeing any new growth?

Any other additives besides Equilibrium?
Do you know your tap water parameters? (usually available online if on a public water system)

Re Seachem Flourish description, you may want to add macronutrients especially as your substrate looks to be plain gravel
For macro element (NPK) fertilization, use Flourish® Nitrogen™, Flourish® Phosphorus™ or Flourish® Potassium™ as needed
 

Simon Cole

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Alto - It looks to me like that second article was produced by an employee of the Union Carbide Corporation in order to meet regulatory requirements. There is no clue as to whether equipment was verified nor the results validated. The results were statistically insignificant and unreliable. It was then accepted and published by an employee of the USA government, without any details of the peer review. To me this article is pretty meaningless. When we look at the number of flaws in the experiment, the article admitting that the data was in part not quantitative, it is hard to find any belief in the results. I would just say that this article has almost never been cited, and that is for good reason. I think that some carbon dioxide is produced, and that they might have found some metabolites leading to it's production, but as you pointed out - this stuff is dangerous, and it is equally dangerous to human health. It is regulated as a biocide and is a known mutagen. The sooner it is packaged properly with chemical gloves, the better.
 

Rloiyao

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Any further information on plant species or source?
Looks as if the old emerse culture leafs are dying
Are you seeing any new growth?

Any other additives besides Equilibrium?
Do you know your tap water parameters? (usually available online if on a public water system)

Re Seachem Flourish description, you may want to add macronutrients especially as your substrate looks to be plain gravel
I think they are Hygrophila polysperma and yes only the old leaves are having problems and I am seeing new leaves.
I am adding excel: everyday 1/3 cap. flourish potassium: every 2 days 2/3 cap. flourish: every 3 days 1/3 cap.

I think I'll stop the excel and try to add NKP from Seachem every other day and flourish every 2 days to see how it goes.
Thanks for all the suggestion, am really struggling.....
 

alto

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would just say that this article has almost never been cited,
I assume you mean the HW Leung article, it was cited in several articles that came up in my search - I didn’t look at it, just included it as it’s the one referenced for Excel by the previous authors

The mechanism of GA forming glutaric acid + carbon dioxide under aerobic conditions is discussed in various papers examining the effects of GA being released into waterways or its use in mining sludge ponds etc
 

alto

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@ Rioiyao you can likely reduce Excel dosage without much adverse effect, but I’d taper off rather than sudden stop
I suspect you’re not delivering levels that will impact livestock and there are many instances of safe usage in aquaria - there’s a short journal somewhere on ukaps of an amazing high tech tank where Excel was the only added CO2/carbon (I’m not that keen as I intensely dislike the smell and have minimal algae ;))

I’d increase nutrients gradually

You might find Filipe Oliveira’s fertilizer regime interesting but note he is adding CO2 and has a nutrient rich substrate
I prefer limited nutrient dosing, if your new leafs look healthy, then add small amounts of NP and monitor plants

 

Tim Harrison

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Interesting fertz regime, I think I may try something like this next time.
 

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