pH myths debunked

[wayne]

I'm assuming that your high hardness is Gh General hardness, a measure of how many Ca and Mg ions are dissolved in, but you have no kH (CO3- ions), the measure of what is termed alkalinity.

Add a kH buffer. Baking soda is one, though as it's Na2CO3 you end up adding Na ions, or a commercial Kh buffer

 

[Orion]

Thanks for that wayne. I never was much in the chemestry department.

 

[TaffyFish]

That was an interesting read Orion, well done on completing your first article.

Since the topic was debunking pH myths, there are a few myths that you have perpetuated so in the spirit of your article I hope that you’ll welcome the debunking of a few more! For example, you say that the Rift Lakes have very hard water, is that really true? The water in Lakes Malawi and Victoria are only slightly to moderately hard. You also say that SA, CA waters are very soft and acidic - that's not entirely true either. Many SA and CA cichlids come from waters which are hard.

The stability of pH and temperature is also an interesting issue. You say of the Rift Lakes, “there is little fluctuation in any water parameters or temperature”. The pH of Lake Malawi varies between 7.7 and 8.6 depending on CO2 content, with higher rates of gas exchange in the surf zone. Lake Tanganyika varies between pH 8.6 and 9.5 and Victoria between 7.1 and 9.0 – these are big differences. With temperature, the surface waters of Tanganyika and Malawi will vary between 24-29 degrees centigrade and deeper water will be 22-23. Victoria, being a shallow bowl in comparison to the deeper Rift Lakes, will have even greater fluctuations in temperature.

I believe that pH 7.0 is just too low for Lake Tanganyikans, 7.5 would be my bare minimum. As you point out yourself, this would be 11 times more acidic than the lowest value you’d find anywhere in the Lake! You say you keep your fish at pH 7.9 so where's the evidence to suggest that pH 7.0 is suitable?

 

[Orion]

The man, the myth, the legend. Good to see you Taff, and thanks for taking the time to read this.

I say that rift lakes have hard water as a generalization(sp). This is by no means a complete, total article that covers every aspect there is to cover. I wrote the entire article in this fashon, in general terms, and also as a good read for the begining aquarist to allow them to grasp a little more knowledge without being overwhelmed by the many, many sources available to them. While you are 100% correct, I may have needed to take the time to elaborate a little more. I feared that this would end up comming back to haunt me.

I did not elaborate enough about the temp. I really should have put in there that they would not vary much within a short period of time insead of leaving it open like that.

Where is your evidence to show that 7.0 is unsuitable? The closest I have to evidence would be when I stoped adding buffer to some of my tanks, the Ph actualy droped over a period of weeks and bottomed at 6.8. I have no idea of the cause, be it the reduction of buffer, or something to do with my local water, but it leveled out at 7.3. My N. brichardi had no difficulty spawning in this water. That has been a while back, and the ph of my tap has steadily increased to where it is now. But in reality, that is just one species out of many, so probably not the best data to draw a conclusion too. I really wanted to put something in there about the minimum pH requirements because that is a very common topic to new enthusiast.

What would you sugest and why?

Agian, thanks for reading and the good critisism Taffy. It is very much welcome.

 

[wayne]

Maybe the effects would be long term ,and maybe it would vary with family , genus or species. As a common example mollies do not do well in soft water as there gill rakers are more akin to those of marine fish than fresh. As fish use their gills for more than breatinhg, (excreting ammonia thro' them , and some osmotic reg) they can do well in very hard water, but do badly in soft.

Taffy is right to point out common myths re: location versus pH. People seem to forget very easily that S America (like Africe) is a big place, and pH varies locally and with geology. While most of the fish we see at least come from soft water that may vary in pH from 2 to 7.5, there are areas of high pH. This is so true of central america, which has the large carbonate geology area of the yucatan peninsula/massif. The native enviroment of convicts can have a pH of between 5 and 8. I recall a conversation with somone who had owned a colony of spectacular livebearers from mexico which had lived efectively in a spring of epsom salts. They all died when he did an unprepared water change and the pH dropped to 8!

I recall an urban myth about a colony of tropheus in florida that were farm escapees and were living in a ditch with a pH in the sixes! This I would like to see, but I do not recall the reference

 

[TaffyFish]

Hi Orion, this is not intended as criticism but as constructive advice. I think your article would have a lot of value for readers on MFT, you have a very accessible style.

I say that rift lakes have hard water as a generalization

No, in fact you say they have very hard water as a generalisation. There are different categories of hardness as shown in the table you provided. There are dangers in generalization - specifically in this article when you mean "Lake Tanganyika" but say "Rift Lake".

I did not elaborate enough about the temp. I really should have put in there that they would not vary much within a short period of time insead of leaving it open like that.

These figures are not time elapsed readings, they show variations according to depth, current, wind, sunshine levels etc and can therefore be simultaneous readings in the same locale. Hence a fish could experience such temperature variations by moving around the lake, changing depth etc. Divers have reported thermal currents in the lake, most apparent at the places where rivers pour into the lake. Sometimes the fish swim through the currents, for others they act as barriers. If you have ever stood in an inadequately heated swimming pool, you'll have experienced warm shoulders and cold feet. This is analogous to surface temperature variation.

Where is your evidence to show that 7.0 is unsuitable?

Ha-ha! That's no way to defend your statement, it's your article my friend and you have admitted an inability to substantiate it. If you want me to quote references for pH minimums in Tanganyikan or other Rift Lake tanks, then I will happily do so once I get back to my texts. I will not draw from my own, limited experience but rather more reputable sources. ;-)
Like wayne says, the effects of incorrect pH on a fish can be long term; they may also be invisible to the hobbyist. Increased stress on the osmoregularity system and gill functions can be evident as dietary problems. So you might find that your fish does not live as long as it might, and might succumb to bloat or intestinal problems which have pH incompatibility as the primary cause. The hobbyist might report success by saying that his fish lived happily for 5 years in pH 6.8 and even spawned, when the same fish might have lived for 12 years in more suitable conditions, had larger spawns more regularly which all produced healthier offspring.

 

[Orion]

Call it criticism or constructive advice. Either way in the manner in which you present it, it helps me to be able to refine, edit and change as need in the article. I did not mean criticism in a negitave way. Everytime I read a post from you, I learn something, so calling me out on what I said is a very valueable experince for me so I can learn from my mistakes. If I didn't want comments on my article, I wouldn't have asked for them.

No, in fact you say they have very hard water as a generalisation. There are different categories of hardness as shown in the table you provided. There are dangers in generalization - specifically in this article when you mean "Lake Tanganyika" but say "Rift Lake".

You are right, I didn't realize that I had done this.

These figures are not time elapsed readings, they show variations according to depth, current, wind, sunshine levels etc and can therefore be simultaneous readings in the same locale. Hence a fish could experience such temperature variations by moving around the lake, changing depth etc. Divers have reported thermal currents in the lake, most apparent at the places where rivers pour into the lake. Sometimes the fish swim through the currents, for others they act as barriers. If you have ever stood in an inadequately heated swimming pool, you'll have experienced warm shoulders and cold feet. This is analogous to surface temperature variation.

I didn't know this. Most of the material I have read would seem to sugest that its fairly consistant though out the lakes. Great annalogy with the swimming pool btw.

Ha-ha! That's no way to defend your statement, it's your article my friend and you have admitted an inability to substantiate it. If you want me to quote references for pH minimums in Tanganyikan or other Rift Lake tanks, then I will happily do so once I get back to my texts. I will not draw from my own, limited experience but rather more reputable sources. ;-)
Like wayne says, the effects of incorrect pH on a fish can be long term; they may also be invisible to the hobbyist. Increased stress on the osmoregularity system and gill functions can be evident as dietary problems. So you might find that your fish does not live as long as it might, and might succumb to bloat or intestinal problems which have pH incompatibility as the primary cause. The hobbyist might report success by saying that his fish lived happily for 5 years in pH 6.8 and even spawned, when the same fish might have lived for 12 years in more suitable conditions, had larger spawns more regularly which all produced healthier offspring.

That wasn't intended as a defence, but more of an honest question. I have read in a few books that a pH of 7.0 is suitable, and other than the limited experinces I have had, thats it. So no, I can't substantiate it. I don't want you to have to do research for me, but if those are the main reasons then I will take it, and research more on it myself. Both wayne and yourself pointed out that just because they can live in different water, that doesn't meen that they will live out full lives. A very basic principal that I overlooked.

I will try to sit down with the information gathered here, as well as some more research and try to draft this over the weekend. I have had some inadequacies pointed out that I will address. Anything of any importance that I may have left out other than the aforementioned?

 

[TaffyFish]

cheers Roger!

 

[Orion]

I have done a lot more reading and researching on the subject, spoken to a few people who have been keeping african cichlids longer than I have been alive, and gotten ahold of a couple of books, and I must say, I've been wrong on several things.

This will get a total re-write as soon as time permits, as the above including some of my own recent experince has gave me a new perspective on the pH/GH issue. To quickly summerize it, the higer the pH and GH, the better off your fish will be.

For now I'm going to leave this stickied to serve as a reminder for me to do the re-write.

 

[discus4everGrl]

Thank you Orion. I actually posted in another post just today about how I don't believe the "your fish will acclimate to any pH you give them" statements I have seen on here are accurate. Acidosis and alkadosis (hope i spelled that right) prolly kills more fish than people even know about because every fish has a range of pH for which their biological process work properly and IMO it's best to either buy fish that are adaptable to a person's tap water or fix the Ph so it is healthy for them. I have been having internal stuggles about bringing this up because it seems to spark such debate.

 

[Orion]

lol, no problem.

Sticking with your more 'normal' fish that you see in LFS, really I doubt that a slightly different PH than what's optimal for them is going to cause great stress.

When you really get down to it, fish keeping is a greatly scientific hobby. Especialy when ones dives into the chemistry of it. The pH/KH/GH/salinity of the water has a masive effect on the way a fish lives. Not to get into it here though.

I think it is generaly accepted that you just don't mess with the PH for a few main reasons:
#1-It's very easy to mess it up and end up with a tank full of fish if your not carefull in doing it. No offence to those amoung us who are new to fish keeping, but someone who is having difficulty keeping simple fish like most tetra's alive, then they sure don't need to be messing with the pH untill they get the basics down.
#2-There's enough do's and don't out there as it is, and the more advanced stuff, like why keeping a proper pH is so important, would undoubtedly turn many people off to fish keeping, so it is kind of swept under the rug so to speak.

Nothing is as simple as 1,2,3. And this hobby is no exception. Best to get the basics down pat first, then move on the more advanced stuff if you want.

I will say this. The best and easist way to make sure you have the best pH for your fish, is to keep fish well suited to your water. If you have soft water, keep soft water fish. If you have hard water, keep hard water fish.

When I wrote this article, I thought I knew enough to share some of my knowledge about it. That was a huge mistake on my part. We as aquarist are constantly learning, and very few in the world can say that they know enough on a subject. Those with more knowledge than I called me on what I said, and several things I could not back up. That sent me into doing lots of research, and brought me to a whole new light, and IMO level in my fish keeping abilities.

Chemistry sucks and hurts my brain. But boy is it important.

 

[TaffyFish]

For Tanganyikans, keeping the KH high is important, if you look after the KH value (13-17 dKH) the pH should look after itself.

Temperature stratification - the top 5-10m can vary by 3 degrees C on a daily basis whilst the next level, 10-60m will fluctuate only on a seasonal basis. The very lowest levels do not vary at all, lying at arround 23 degrees C. I found this only today in "The State of Biodiversity in Lake Tanganyika" edited by Pattison and Makin, 1998

 

[Orion]

I've not got that far in my books yet, but I don't think I've read about the fluctuation of temp where the esstuaries and rivers dump out into the lake. I know the KH is very different, and that is part of the reason that the endemic species have stayed so isolated. Not that it matters, just my curiosity. As the chem difference and all the silt being dumped into the lake at these points seem to be enough to keep most lake fish away.

Thanks for the tid-bit TaffyFish. Keep them comming!

 

[discus4everGrl]

Orion wrote -really I doubt that a slightly different PH than what's optimal for them is going to cause great stress.-

In most cases a slight change is adaptable. However, don't forget that pH is logarithmic. In case anyone doesn't know what that means is that each degree is 10X more acidic or alkaline than the previous. For example 6 is 10 times more acidic that a reading of 7 and 5 is 100 times more acidic than 7. So yes, it may seem small to us, but the scale is logarithmic.