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Is expensive bio media worth it?

Is expensive bio media worth it?


  • Total voters
    78
Hi @jaypeecee
It would be helpful if you could share how useful ORP readings are for you.
Thank you
Hi @aquanoobie

I have been closely monitoring ORP in one of my tanks for just over six months. My objective was to see if it would provide a reliable 24/7 indicator of dissolved organic compounds/matter (DOC/DOM). After stabilization, the figure that I am seeing most of the time is 400 - 425 mV at a pH of typically 6.7. I recently sent a sample of this tank water to a test laboratory. They measured Total Organic Carbon (TOC) and the result came back as 2.23 mg/l. Why am I interested in TOC, you might ask? And my answer is that dissolved organics can potentially lower dissolved oxygen, etc.

The nett effect of keeping ORP high is that I'm seeing no significant algae or Cyanobacteria growth in this tank.

JPC
 
Hi @aquanoobie

I have been closely monitoring ORP in one of my tanks for just over six months. My objective was to see if it would provide a reliable 24/7 indicator of dissolved organic compounds/matter (DOC/DOM). After stabilization, the figure that I am seeing most of the time is 400 - 425 mV at a pH of typically 6.7. I recently sent a sample of this tank water to a test laboratory. They measured Total Organic Carbon (TOC) and the result came back as 2.23 mg/l. Why am I interested in TOC, you might ask? And my answer is that dissolved organics can potentially lower dissolved oxygen, etc.

The nett effect of keeping ORP high is that I'm seeing no significant algae or Cyanobacteria growth in this tank.

JPC
Hi @jaypeecee
ORP is a fascinating tool, I have read a long thread about someone having access to a lab with Total Organic Carbon TOC test equipment. They organized a group of aquarium hobbyists with planted and fish only tanks. They were sending water samples for analysis in order to link the TOC levels to algae. Unfortunately no link was found.

In your experience, what ORP mV range values you see? What does it say before and after water change. Or, did you test water where filter media was washed? Theoretically the wash should have lower numerical value than it's tank water, right? I find ORP and TOC values difficult to interpret.
 
So is anyone here actually using plastic pot scrubbers in their filter? I'm contemplating getting some instead of biohome ultimate, it would be good to hear from other users out there.
Hi @Muso1981
I have tried and found it to be a bust, it has deteriorated into gummy like consistency. So it looks like the brand name sponges are worth the price.
 
They organized a group of aquarium hobbyists with planted and fish only tanks. They were sending water samples for analysis in order to link the TOC levels to algae. Unfortunately no link was found.
Hi @aquanoobie

Yes, I am very familiar with that thread. But, I think you'll find that the results of that analysis were imported to an excellent web site run by a guy that used to be a member here on UKAPS. His name is Marcel Golias and the following is the relevant page from his website:


The results of the TOC (and other water parameters) are shown in tabulated form and they are credited to Jeffrey K. Funk, PhD. The outcome of this and associated work is finally summarized as:

"The imperfect activity of mineralizing bacteria and the consequent accumulation of toxic organic substances in the water is therefore, in our opinion, the main reason for the appearance of algae in the aquarium!"

I interpret this as suggesting that the mineralizing (heterotrophic) bacteria are running low on nutrients of which oxygen and phosphorus come to mind.

JPC
 
In your experience, what ORP mV range values you see? What does it say before and after water change.
Hi again, @aquanoobie

The tank to which I referred in post #161 is one for which I don't do water changes. What? I hear you say. It is a tank in which I let the plants purify the water. Apart from a surface skimmer to create water flow and keep the water surface clear, the plants remove ammonia, nitrite and nitrate. They also consume any surplus heavy metals, etc. I have an inert substrate in this tank and the only plants are epiphytes (Java Fern). I keep [CO2] at around 10 ppm. I monitor the tank using a conductivity meter, a Seachem Ammonia Alert, an ORP meter, a pH meter and a couple of Hanna Checker photometers (phosphate and iron). No doubt I will have forgotten to mention something. Oh, yes - and the tank is home to Vietnamese Cardinal Minnows.

ORP briefly drops around 50 mV when I add a dose of Seachem Flourish Iron, which contains ferrous gluconate and this is an organic compound. Right now, ORP is 421 mV.

JPC

P.S. I feel that I must apologize to the OP (@noobscaper) for steering this thread from its original topic. Unfortunately, I've yet to find a way of preventing this from happening.

JPC
 
Hi @jaypeecee
Thank you for posting this link,

Aquarium

The table has lot of data in it but it doesn't support the conclusion much that elevated TOC directly or indirectly causes algae. There are too many variables. Then, this topic leads to this excellent summary post by @AndyMcD ,

What exactly causes BBA? Part 2 - Bacterial imbalance

He talks about a symbiotic relationship between BBA and heterotrophic microbes.

And then you present your eye-opening experiment:
The tank to which I referred in post #161 is one for which I don't do water changes. What? I hear you say. It is a tank in which I let the plants purify the water. Apart from a surface skimmer to create water flow and keep the water surface clear, the plants remove ammonia, nitrite and nitrate. They also consume any surplus heavy metals, etc. I have an inert substrate in this tank and the only plants are epiphytes (Java Fern). I keep [CO2] at around 10 ppm. I monitor the tank using a conductivity meter, a Seachem Ammonia Alert, an ORP meter, a pH meter and a couple of Hanna Checker photometers (phosphate and iron). No doubt I will have forgotten to mention something. Oh, yes - and the tank is home to Vietnamese Cardinal Minnows.
Not doing water changes doesn't surprise me when you have so well balanced ecosystem. Though few things I want to ask, isn't there a problem with the substrate without plant roots not supplying oxygen? No black zones? Next is filtration, do you use lots of biomedia or none? This would have an impact on your water quality in terms of organics and ORP.
ORP briefly drops around 50 mV when I add a dose of Seachem Flourish Iron, which contains ferrous gluconate and this is an organic compound. Right now, ORP is 421 mV.
In any case, having ORP +421 mV without water changes disproves both of the above articles. According to common knowledge, not necessarily correct one, you should have algae everywhere and ORP in minus territory. But you don't. You have extremely clean water despite organics accumulation of hormones, fish waste and other scary compounds "causing" algae.

You are running an impressive experiment, where can I read more?
 
You are running an impressive experiment, where can I read more?
Hi @aquanoobie

Many thanks for your feedback.

There isn't a great deal more to tell you. It was the result of learning that aquatic plants preferentially uptake ammonia/ammonium instead of nitrate. So, fish excrete ammonia and we normally hand over the job of conversion to nitrate by using nitrifying bacteria and/or archaea. But this encourages accumulation of nitrate in the water column - unless we also incorporate denitrifying bacteria in the so-called biological filter. And build-up of nitrate in the water column (along with phosphate and iron) must surely encourage algae and/or cyanobacteria growth.

You have extremely clean water despite organics accumulation of hormones, fish waste and other scary compounds "causing" algae.

Yes, it's paradoxical, isn't it? It makes me wonder if aquatic plants can uptake organic compounds. Or, is it heterotrophic bacteria mineralizing DOC to inorganics, which can then be uptaken by the plants? I suspect the latter. Now, all this is requiring me to read a lot of scientific papers. My background is not in the Life Sciences.

I'll leave it at that for now. But, expect to hear from me again - probably tomorrow.

JPC
 
It makes me wonder if aquatic plants can uptake organic compounds.
They certainly do. Auxin, gibberellin, cytokinin, ethylene, and abscisic acid are the five major classes of commonly-used plant growth hormones, and they have a variety of applications in commercial agriculture and horticulture. I have to confess, I have used the synthetic phytohormone triacontanol (C₃₀H₆₂O) in terrestrial horticulture. Generally, the results of leaf spraying just once are outstanding levels of auxiliary shoot growth, which results in very bushy growth and less apical dominance. Given that stem plants are often cut, I would suggest that natural plant growth hormones in the five aforementioned classes are often released into aquarium water and could well trigger algal blooms. Notwithstanding, simple sugars are relatively easy for plants to absorb, and there is extensive evidence that plants uptake even larger organic molecules, as evidenced in studies tracking radiocarbon isotopes from application sites into plant tissues. The role of plants in bioremediation is often overlooked, but increasingly there is a favour towards macrophytes being used to mitigate and remediate environmental pollution caused by heavy or cyclic-aromatic hydrocarbons.
 
Never mind
 
Whoops, didn’t read the title correctly
 
Hi @Simon Cole

Good to hear from you and thanks for such a detailed reply.
The role of plants in bioremediation is often overlooked, but increasingly there is a favour towards macrophytes being used to mitigate and remediate environmental pollution caused by heavy or cyclic-aromatic hydrocarbons.
I have several papers that deal with the role of aquatic plants in bioremediation. I'll take a look at those. Let me ask a simple question - is it possible for epiphytes to uptake organic compounds without the intervention of bacteria or other microbes? I was under the impression that mineralization of organic waste in the water column was a prerequisite for aquatic plants being able to uptake nutrients. Is this not correct?

JPC
 
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Hi @Simon Cole

Good to hear from you and thanks for such a detailed reply.

I have several papers that deal with the role of aquatic plants in bioremediation. I'll take a look at those. Let me ask a simple question - is it possible for epiphytes to uptake organic compounds without the intervention of bacteria or other microbes? I was under the impression that mineralization of organic waste in the water column was a prerequisite for aquatic plants being able to uptake nutrients. Is this not correct?

JPC
That is generally correct. Everything @Simon Cole said is true as well, but what he's talking about are more like special case scenarios and not how plants typically obtain their nutrition. It can't be overstated how much it varies by species and the plant world is filled with specialists that are capable of feats that are impossible for everybody else.
 
That is generally correct. Everything @Simon Cole said is true as well, but what he's talking about are more like special case scenarios and not how plants typically obtain their nutrition. It can't be overstated how much it varies by species and the plant world is filled with specialists that are capable of feats that are impossible for everybody else.
Hi @ElleDee

Many thanks for the clarification - it is greatly appreciated.

JPC
 
Hi @jaypeecee
The epiphytes, as other plants and substrate, are covered by multilayer of microbial biofilm converting compounds back and forth which feeds the plants.
 
is it possible for epiphytes to uptake organic compounds without the intervention of bacteria or other microbes?
Good and useful question, grateful you asked because it's an interesting subject.

The opinion of one researcher is rather interesting summary on stomates:

"It is assumed that all liquid uptake of water and dissolved substances occurs exclusively through the leaf cuticle, and not through the stomates. There are two pathways by which exogenous chemicals may traverse the distance from the leaf surface into the symplast; a lipoidal route and an aqueous pathway. Compounds that penetrate the cuticle in the lipoidal-soluble form do so principally in the non-polar, undissociated form, whereas compounds that enter via the aqueous route move in slowly, and their penetration is greatly benefitted by a saturated atmosphere."

Obviously the stomata gets a lot of attention, but not a lot of people know that there are stomata on the leaf surface as well as the underside and that this can be an environmental adaptation too. The two pathways that exist in stomatal pores indicate that they can and do adsorb a range of polar an non-polar organic molecules very effectively and include many organic molecules with considerable molecular weights.

However, in addition to the stomates there are aqueous pores with average pore radii ranged from between 0.45 to 1.18 nm that allow organic ions with molecular weights of up to 800 g mol−1 to penetrate plant cuticles (Schönherr, 2006). In hot arid environments, plants use these pathways to emit hydrophilic carbohydrates, and the volatile compounds water and ethanol. This helps to protect their leaves from photoinhibition and to reduce water loss. When you smell lavender, you are experiencing that process.

Aside from the two major pore types, there is lipid-soluble adsorption of organic molecules across the unbridged leaf cuticle, the enormous efficiency of roots to both allow passive and pumped pathways into both cellular and vascular plant tissue, and a surprising range of newly-discovered pathways across the leaf cuticle that are far smaller than known types of pores and have been identified in varying plant species. The function of the latter is interesting because we do not know very much about the polarity or molecular weight of the organic molecules that can bridge, but there is a growing body of evidence from radiocarbon isotopic analysis and microscopy that shows they exist and can be quite abundant. My opinion is that it is rather hard to find an organic molecule that could not be absorbed rapidly by aquarium marcophytes.

The other side of the equation is a lot more interesting and could explain why algal blooms and various other biological community changes occur, and that is that aquarium plants could emit organic molecules passively (in addition to when they are cut or damaged). That fits well with the belief that macrophyte growth has some biochemical mechanism for inhibiting algal growth, and this would be especially relevant to both emergent and aquatic plants that may well have evolved such competitive adaptations. For a rheophyte, it is fairly useless because the biochemical inhibitor would get washed away in the water current, but for still water plants it could be more advantageous, especially as a community response happening across a wide population. This is one of the great unknowns about aquatic communities. Why should they not have evolved chemical defence mechanisms when we know that they do promote root horizons of microbial growth to benefit nutritional uptake.

On a side note, ever wondered why Rotala Wallichii seems to stop growing sometimes, or why Ludwigia Palustris var. Super Red Mini seems to turn brown and die in hi-tech. Could there be phytohormones in the water causing their stomata to close and the plants to suffocate I wonder. Abscisic acid would be a likely candidate for this mechanism if the plants were generating it to cope with stress. This explains both why established tanks are more stable and conducive to aquatic growth and newly planted tanks can take off quickly. Advanced filter media like Purigen could have the ability to mitigate any undesirable organic molecules if they were present, but then what about the desirable ones. Many aquarists find themselves in a juxtaposition over which approach to take, and I guess that I would suggest that expensive filtration media could be ideal for new tanks and short-term applications, but in reality organic molecules add considerable unpredictability. Future research could look at how we measure them in aquarium water, but if we did discover a naturally-occurring algal growth inhibitor that is safer than glutaraldehyde then we would be laughing. That would be my second nomination for the UKAPS Nobel Prize award in addition to lean dosing.

@jaypeecee - sorry that I have not answered you question relating to epiphytes. I guess that microbial symbionts (like but probably not including Trichoderma T-22 ) have an inherited role in feeding epiphytes like @aquanoobie suggests, and perhaps some are more parasitic (about 1% of angiosperms, found in almost every biome) but we don't generally keep them. I cannot think of any parasitic epiphytes in aquariums, and I am not sure they would need to behave in that way unless they were targeting certain organic nutrients like carbohydrates. Non-parasitic ones may well utilise microbial symbionts, but many also grow in-vitro in sterile conditions.
 
Though few things I want to ask, isn't there a problem with the substrate without plant roots not supplying oxygen? No black zones? Next is filtration, do you use lots of biomedia or none?
Hi @aquanoobie

Me again!

A few additional notes:

[1] The substrate is a 1 - 2 cm layer of silica sand and the grain size is 1 - 2 mm. I use a Python gravel cleaner on it roughly every 4 to 6 weeks.

[2] I don't use any biomedia. I have a small coarse sponge inside the surface skimmer.

[3] I'd like to be in a position to specify the lighting parameters - particularly PAR. But, at present, I haven't got round to purchasing one of the Apogee products. The light itself is a Sera Nano LED Light with default LED clusters running at 50% brightness.

[4] No nitrifying bacteria and/or Archaea have been added during the tank's entire life, having been started on 13 October 2021.

[5] Tank water is remineralized RODI water.

[6] Tank water pH is maintained 24/7 at 6.5 +/- 0.2 by a continuous dribble of CO2.

That's all for now.

JPC

POST EDITED ON 16 MAY 2022 TO ADD IMAGE

Tank5.jpg
 
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The other side of the equation is a lot more interesting and could explain why algal blooms and various other biological community changes occur, and that is that aquarium plants could emit organic molecules passively (in addition to when they are cut or damaged).
Hi @Simon Cole

Ah, that's got to be allelopathy, I guess? This was referenced quite recently but I can't remember the actual thread.

Anyway, thanks for all your input - particularly the stuff about aquatic plants and bioremediation.

JPC
 
I cannot think of any parasitic epiphytes in aquariums,
This is complicated by so many aquarists insisting on calling their Anubias, Microsorum etc 'epiphytes' when they are lithophytes. :)
I have given up being angry about it, or trying to put them right. Mostly. :)
If they are growing on wood that is not part of a living tree xylophyte appears to be the most appropriate term, although it also has the meaning of 'woody plant' so it's not ideal.
Epiphytes, by most definitions, use another plant purely for support and are not parasitic.
 
@sparkyweasel - Agreed and supported :thumbup: The definitions of epiphyte we see in many dictionaries or encyclopaedias are incorrect. Epiphytes are plants living on other living plants. Algae can be epiphytic to aquatic plants. You are right, epiphytes do not need to be parasitic. A quick check online confirms that one of our sponsors Tropica are not using the term epiphyte to describe the rhizome plants that you mention, whereas Aquasabi and Buceplant are two online websites where the term is used incorrectly to describe them. When it is plant living in fast moving water then it is a rheophyte, and as you point out, if it is living on rocks then it is a lithophyte. A plant living on dead wood is certainly a saprophyte. I can see two papers defining woody terrestrial shrubs as xylophytes (Ying-bo, 2008; Do Kim et al, 2011) and I reckon this was due to mistranslation or misinformation. Saprophytes do not need to saprotrophs nor can they be other non-photosynthetic microbes like fungi, as I have noticed from another incorrect online definition; they are limited to plants. None of these terms are mutually exclusive when we describe a species as opposed to a community.
 
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When it is plant living in fast moving water then it is a rheophyte, and as you point out, if it is living on rocks then it is a lithophyte. A plant living on dead wood is certainly a saprophyte.
Then, our Buce, Anubias and Ferns can be classed as all three?
 
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