Study: Alkaline waters in the Amazon!

[DiscusBR]

Hi everyone,

In another thread I asked if people knew scientific studies about ph and discus. Later, I saw a reference that Eric (erictdallas) made to a research conducted in the Amazon. I did a search and found information about it. Between 1982 and 1991, research institutions from Brazil (INPA and CENA) and from the United States (Unversity of Washington and NASA) collected data about water paramaters in several locations in the Amazon. The map with the locations and with an explanation of the methodology can be found at:

ftp://daac.ornl.gov/data/lba/surf_hydro_and_water_chem/CAMREX/comp/Pre_LBA_CAMREX.pdf

A table with the results can be found at:

ftp://daac.ornl.gov/data/bluangel_harvest/camrex/data/chemistry/chemdata.txt

The study found that in a very significant number of locations ph was above 7.0 and that some areas had ph values of 7.4 !

This study debunks the myth that discus come only from acid waters. It also provides support for those who think that clean water, with no ammonia and nitrites, and with a stable ph is much more important than a acid one.

[ericatdallas]

(IMHO/guess) I think 'back in the day', the Discus hobbyist saw a correlation of success and low-pH. They might not have thought of the fact that in low pH, harmful ammonia becomes the less harmful ammonium ion. (my guess...) so they had to be less rigorous in their WC routine. Also, low pH means some external parasites are reduced. <shrug>

http://www.ozcoasts.org.au/indicators/images/oze_fs_004_09.jpg

[DiscusLoverJeff]

So do these studies "debunk" the theory that discus "need" a softer water or can they be safely bred in harder water as William Palumbo has proven over and over again?

When I read studies like these and countless threads on water conditions for home raised and for wilds, it all seems to say the same thing actually that discus can survive and breed in almost all types of water conditions, but they prefer softer cleaner water?

I am so confused, Lol.

Thank you for the interesting read.

[DiscusBR]

(IMHO/guess) I think 'back in the day', the Discus hobbyist saw a correlation of success and low-pH. They might not have thought of the fact that in low pH, harmful ammonia becomes the less harmful ammonium ion. (my guess...) so they had to be less rigorous in their WC routine. Also, low pH means some external parasites are reduced. <shrug>

You raise an interesting possibility. May be some veterans can shed some light.


So do these studies "debunk" the theory that discus "need" a softer water or can they be safely bred in harder water as William Palumbo has proven over and over again?

When I read studies like these and countless threads on water conditions for home raised and for wilds, it all seems to say the same thing actually that discus can survive and breed in almost all types of water conditions, but they prefer softer cleaner water?

I am so confused, Lol.

Thank you for the interesting read.

I focused the discussion on ph, not water hardness, which is another interesting topic. For me, the most important message, especially for beginners, is: if you have alkaline tap water, don´t fight with it. Forget about correctives and buffers. More important than an acid ph is a stable ph.

[DiscusLoverJeff]

"Forget about correctives and buffers. More important than an acid ph is a stable ph. "

Good point!

Thank you again for the post and read, I understand more and more from you people who go through great lengths to provide newbies and experts alike with quality information.

[discolicious]

The studies points out that pH in rivers in Brazil can be as high as 7.4+, but does it indicate that discus are found in those rivers? From what I've read, the early discus researchers simply checked the pH of the water where they were collected. That doesn't mean that the pH isn't higher in other places, nor does it mean that discus are not very adaptable. But the question would be, if in nature, discus tend to be found only/primarily in rivers of lower pH, the parameters may be necessary for breeding but not for survival. If that is true, it is unlikely that they would venture to waters where they could not successfully breed. (This too, may not be true for tank raised discus, as others have indicated they had success in harder waters with lower pH.) My only mated pair only lays eggs soon after a water change with soft water of 6.2 pH, but I don't know if that's due to the pH or the soft water, or just the fact that it's "clean".

[John_Nicholson]

Ask anyone that has ever heard my talk...I have been preaching this for years.

-john

[DiscusBR]

The studies points out that pH in rivers in Brazil can be as high as 7.4+, but does it indicate that discus are found in those rivers? From what I've read, the early discus researchers simply checked the pH of the water where they were collected. That doesn't mean that the pH isn't higher in other places, nor does it mean that discus are not very adaptable. But the question would be, if in nature, discus tend to be found only/primarily in rivers of lower pH, the parameters may be necessary for breeding but not for survival. If that is true, it is unlikely that they would venture to waters where they could not successfully breed. (This too, may not be true for tank raised discus, as others have indicated they had success in harder waters with lower pH.) My only mated pair only lays eggs soon after a water change with soft water of 6.2 pH, but I don't know if that's due to the pH or the soft water, or just the fact that it's "clean".

Yes, the study says nothing about discus. Thus, it does not correlate ph parameters with the presence or absence of discus. But it does show that relatively alkaline waters are more common In the Amazon than one would assume reading the literature about discus. There is a clear need of more research on the topic.


Ask anyone that has ever heard my talk...I have been preaching this for years.-john

Sorry John, but what exactly have you been preaching?

[Darrell Ward]

Ask someone who has actually collected discus in nature what the pH of the collection water was? I seriously doubt it was anywhere near 7.4. I'll bet they only found discus in blackwater, since discus seem to seek out these areas to live and reproduce. But, it certainly doesn't mean they can't live in pH above neutral, because we know they can.

[ericatdallas]

Here's an article...http://www.fishchannel.com/media/freshwater-aquariums/species-info/discus/wild-discus.aspx.pdf


Discus are found in all three types of Amazonian water: clear, white and blackwater. And while the pH may vary drastically
from 4 to 7.4, waters harboring discus have one thing in common — they are very soft (less than 1 dKH).

Further strengthening the theory that a more natural (not necessarily better) environment is one that has low TDS and not necessarily low pH.

Anyway, I think we all agree that different people have different luck with different discus...etc.

Also, it doesn't always matter what the natural environment is... invasive species are sometimes invasive b/c the new environment is actually conducive to survival. Even looking at human, you stick twenty people in a room and ask one person to change the thermostat, you'll probably have half the people happy and the other people cold or hot.

[Jhhnn]

Ask someone who has actually collected discus in nature what the pH of the collection water was? I seriously doubt it was anywhere near 7.4. I'll bet they only found discus in blackwater, since discus seem to seek out these areas to live and reproduce. But, it certainly doesn't mean they can't live in pH above neutral, because we know they can.

Degen indicates that discus are found in clear water tributaries having a PH of 6-7. With the possible exception of heckels, they're apparently not blackwater fish, where ph is much lower, near 4. Few species are.

That matches other truly authoritative sources, none of whom I can cite atm, who offer that the ph of productive waters in the dry season is ~6 or so.

Discus pioneers, particularly in Europe, had a lot of trouble with what they thought were water parameters, and went to great lengths to obtain suitable water or to alter what they had. In retrospect, their issues may have been due to pollutants, environmental protections being largely non-existent at the time. They simply didn't have the means to test their water for exotic industrial and agricultural pollution. Schmidt-Focke used water from a particular spring before switching to water filtered thru activated carbon and then peat, both of which remove organic pollutants. He goes on about it at some length in his 1989 book, which I still have.

What Nicholson, Palumbo and others have shown us is that discus really are highly adaptable in terms of PH and hardness. Discus are, however, apparently quite sensitive to unstable conditions & pollutants of all kinds, whether introduced or created in our aquaria. Our own test kits tell us little more than what they did back then, but our water suppliers often use extremely sophisticated means to detect and ameliorate chemical pollutants. Tap water here in Denver isn't just water, for example, it's a highly refined and much altered commodity. The fact that it's collected at high altitude from snowmelt means it just starts out better, with fewer pollutants. Downstream suppliers have a much tougher job of it, as do hobbyists who depend on water from relatively shallow wells in agricultural areas.

[discolicious]

I think it would be great if sites like this hosted controlled "research" conducted by the members. Suppose members agreed to a 6 mth research following well laid out guidelines and documenting specific information that would then be compiled and posted. It seems to me that some fairly concrete conclusions could be drawn from this information as long as guidelines were followed.

For example, suppose a large number of members, starting with 2" juvies, with differing ranges of pH and DH, agreed to follow different wc schedules, under different filtering methods, (with same feeding schedules, diets, and temperatures) and then list measured growth rates, diseases, behavior, deaths, over a 6 month or year study, we might draw some interesting conclusions that would be very helpful to those interested in discus but confused by the incredible disparity of advice they receive.

(Another study could be done just focusing on the varying conditions in which discus will breed and raise young: success rates, frequency, survival of fry, etc.)

To date, almost all of this information is scattered throughout thousands of posts in anecdotal form, giving a fairly obvious (and confusing) picture that many people are having success with discus under various conditions. Unfortunately little controlled statistical information exists that might clarify "best practices" or weed out myth, exaggeration or false correlations, and nail down what is absolute. (Yes, I know some of you will throw rotten tomatoes at me for admitting it, but if research showed no statistically measurable difference in raising juvies in tanks of "x" parameters with daily wc of 90% and those raised in the same parameters with once a week wc of 30%.. well, I'm doing the latter!.... go ahead, throw them, I know you want to). :D

At the same time, think how relieved we would be to discover that most parameters are fine for growing out discus as long as nitrates are below "x", or if we discovered that it isn't so much the nitrates but due to slime coat substances that inhibit growth.. but can be removed by using a protein skimmer and charcoal (just an example)... this is the kind of information that I would love to see as "proven".

Tom

[John_Nicholson]

Yes, the study says nothing about discus. Thus, it does not correlate ph parameters with the presence or absence of discus. But it does show that relatively alkaline waters are more common In the Amazon than one would assume reading the literature about discus. There is a clear need of more research on the topic.



Sorry John, but what exactly have you been preaching?

That discus do not need a low Ph to do well. That jacking with your Ph is one of the worse thing for a new discus keeper can do. The main thing is to keep your water clean.

-john

[Jhhnn]

That discus do not need a low Ph to do well. That jacking with your Ph is one of the worse thing for a new discus keeper can do. The main thing is to keep your water clean.

-john

When I started thinking about coming back to discus 2.5 years ago, I had the good fortune to find Simply, and to follow John's advice, which is much the same as other long time successful discus keepers. The 4" fish I purchased from Kenny (who told me the same thing) have grown out to be quite large & healthy in Denver tap water. Don't just take my word for it, ask the members who've seen my discus, blkrob & obsessed. Good stock + large diligent changes of Denver tap water have served me well. My newest batch, eight VF's from Kenny are doing just as well as the others- eating, pooping, growing! & playing their discus games. Because I change a lot of water on a near daily basis, I can feed them with impunity, insuring maximum growth basically w/o a care as to water quality. It's mostly fresh everyday. Kenny provided healthy vibrant stock, and lots of fresh tap water & a varied diet did the rest...

[plecocicho]

Most of the south american river and lake systems carry soft to extremely soft water, exceptions being some trans andean river sytems, some peruvian river such as Rio Alejandro, south brazils rio Bonito, Lake Titicaca. All those have alkaline and soft to medium hard water. Traditionally, amazon water bodies have been lumped into three categories: White water which are mineral (amazon standard) and nutrient rich, productive, ph between 7 and 7, 5 and soft. Fish that inhabit these water have the greatest plasticity in their water requierments. many of the well known aquarium fish live in hose waters. Clear waters are very soft and acid (5 to 6, 5) nutrient and mineral poor. At least wild fish from those habitats need soft and sligthly acid water to thrive. Blue discus lives in those habitats and has the greatest ecological plasticity for water parametrs considering discus. Black waters are extremmely soft,extremelly acid (3-5), very nutrient and mineral poor. Greens and heckel discus live there. Since heckels live in the extremest water parameters, they have little ecological plasticity as they have evovlev to cope with tahat enviromet through etological and phisiological adaptations: smaller sizes compring to the other species, adaptations to the fruit diet, chloral cells for mineral accumulations, etc.Considering water parameters, the best anwsers can be giving by the fish collecters themselves.