Buffering Is KH Necessary

It would seem unwise to operate a tank with no buffering.

isn't one of the problems with distilled or dionized water that very small changes cause large swings?

Joe

 

Hi,
I hate the term dispute, this is just a discussion and I don't mean to be rude with anyone. Excuse my english expressions if sometimes my comments seem too direct. I'm also open to change my mind about KH...

Anyway,

To answer BigFlusher, using distilled is a bad idea as it has a GH of 0 and especially a very low conductivity, it will kill every fish. A very low GH, below 1, is present in most amazonian rivers where live most of our fish. Asian waters are also very soft. So, it is not the low GH that necessarely kills the fish, but the conductivity of the water that can make osmotic pressure too high on fish. Many breeders successefully keep wild Discus in KH 0 and GH near 2 or lower. Many asian breeders have a great success with KH 0 and GH near 2-3 with the most sensitive critter: high grade CRS

I questionned my self about this KH when I started keeping high grade RCS. Having a low KH, even 0, will help keep these shrimps at a PH in the 6 range in a stable manner, without using any CO2 or active soil. This is because water will be closer to CO2-KH-PH table. When no CO2 is injected, CO2 in water is near or lower than 5ppm, it will be never higher.

Akadama soil, will drop the PH by dropping the KH near 0 for example. Yet, CRS breeders are having a great success with it, when they don't inject CO2 (most don't inject CO2 anyway, as breeding tanks are usually substrate only tanks with just some mosses).

Now, in our planted tanks needing CO2, if the KH was 0, the PH fluctuations when CO2 is injected during the day will be very extreme. Thus, injecting CO2 without KH, can be dangerus for fish. Same thing with active substrates that will drop the PH. If no KH is present, than these soils can drop the PH too low by releasing organic or other acids. This could cause a too low PH for some species, especially if under 5.

Also using clay based soils can drop the PH too low if KH is 0, but there will be no fluctuations of the PH if you don't alter things by injecting CO2

In a CO2 tank, having some KH is mandatory in my estimations to avoid killing fish with extreme PH limits. If you don't inject CO2, having a KH of 0 will be the easiest way to have a stable PH in the 6 and lower range, depending on type of substrate and roots you have in tanks. Your fish will be happier than ever with these stable conditions

When Tom is back, hopefully he can add some light on this

 

Hy everybody

Resuming
I have two tanks, one with 20 G with tropical fish and other with 100 G with goldfish.
The results was:
20 G - ph=6 and kH = 1º
100 G - ph=6 or bellow and kH =1º
Note that ph test is form API and the test was made before the light turn off and kH test is also from API but note at the frist drop turn water turn yellow and i don´t no really if it is 0 or 1 degree.

Then i have put Ca(HCO3)2 and rise the ph to 7,2 and today i have again test the ph and what i have found, in the 100 G with goldfish the ph is at 7 but the in the tabk with 20 G where the fish died from the night to day it has 6.4 !!!! why ????
In the two tanks i have now the kH at 2º

Why in the tank of 20 G the ph is getting low do fast? i have the same kh !!!

Regards

 

i contributed to this mix-up and hope it never happens again; lets see if I have a better understanding. I'll be quick about it.

Now, I know that within reason, water with 2 dGH or higher is good (depending on what we are keeping)

Ranges of KH will depend on the source of water. It has a relationship with carbonic acid useful to CO2ers, but is otherwise benign - It is better to play the hand your dealt then to cheat.

KH can also drift up, thats bad (unless your adding CO2).

If you made it to here, some of the statements must be right. Right?

Just one more question, can we always detect KH (carbonate hardness) if we use buffering capacity testing?

 

Hy
No one must ask for apologies, the suggestions that all of you gave was trying to help me.
But i think the kH is very important, i must maintain the tank with 100 Gallons at ph 7 or more not for the plants but for the fishes, Goldfish don´t like acid waters like ph at 6, if they can live don´t mean they like it, at this point i disagree form Tom Barr, sorry.

On the 20 Gallons tank i could get a middle solution like put the ph at 6.5 for example, but yesterday the ph was at 6.4 and today it is at 6.2

Now the question is: If the plants and fish don´t care with low kh or gh it´s fine but a fish that like a ph of 7,5 and after a few days it´s a 6 well i think that this don´t give good health, i sould have some kh or i will have ph going down.
One more question if i keep the ph at 6 when a make a water change i will produce a ph swing since the water that i use have ph of 7,5

Sorry this questions but i think they are important i think

 

i still think it is unwise to operate most (all?) tanks with no buffering.

i still contend one of the problems with distilled or dionized water that very small changes cause large swings?

if pH is not of any concern and will not harm any fish, why do i see such a slow down and die off of bacteria in filters when the pH drops below 5.0-2 or so.

everyone can tell me how stupid i am and maybe i am not all that bright, but given that fish are not the closed system mammals are, i simply cannot buy that fish are not harmed by ph ranging below 5 and down to 4.6, especially goldfish and livebearers ismenio.

ismenio: use the baking soda and bring the KH up to at least dKH 5, dKH 8 or 9 won't hurt. 6 grams baking soda for each 50 liters will raise the dKH 4, for the 20-gallon tank 2 grams for each 4 dKH you want. in your 100-gallon tank add 45 grams for each 4 dKH desired.

i don't care if i get barr'ed for disagreeing.

stupidly yours,
Joe

Joe

 

Hi,

Baking soda in those ammounts is a bad idea, you add too much sodium.
Again, BigFlusher, using RO/distilled is bad because GH and conductivity are near 0, fish will explode their skin. It's not the PH.
Distilled has a PH around 6-6.5. If you put fish in it though, it won't live a long time because of the osmotic shok due to a conductivity near 0

I still have a question for Tom. If you use distilled where you add only GH, so KH of near 0 in a CO2 tank. By expierience, the PH can be in the 4 range with some soils or CO2. Don't you think that most species won't make it in the long term in such a PH? Having some KH in a CO2 tank looks wise, also in non CO2, depending on soil.

 

Has Tom Barr say the ph swing over waters changes do not kill fish like discus that are very sensitive and i can agree with that but i can not agree with maintain others species that like uppers ph like 7,5 or 8 on ph like 6 or bellow, how can i rise the ph without rise the kh?

Regards

 

To Tom Barr

By the way, let´s suppose for the next examples all are planted tanks

1º Scenario

Tank with the water source with PH at 7,5 ph and KH at 4º with no CO2 ,after a month the ph will maintain or drop? I think will drop

2º Scenario

Tank with the water source with PH at 7,5 ph and KH at 4º and with CO2 ,after a month the ph will maintain or drop? I think will maintain.

I think when we add CO2 to a tank we are helping to maintain the KH stable since the plants have a better source for CO2
Relative to ph it seems have a direct relation with KH; high ph equal to high kh.
And the table PH-KH-CO2 it seems to be wrong, with a ph of 6 with kh 1º i will have 30 ppm of CO2 that is false sinse i don´t inject CO2 in the tanks.

If i´m wrong please explain.

Regards

 

I understand you guys know all... but i do not believe goldfish or live bearers are likely to be harmed as quickly by adding a small amount of salt than subjecting the goldfish to pH's in the 4's.

at some point a little common sense should prevail.

i see quite a number of very educated and competent people out there recommending buffering and some attention to pH. I cannot believe everyone of them is wrong, a fraud, or a liar.

If you don't like baking soda, use plaster of paris or quick-lime or something. Given the crisis situation that ismenio is in I would go with straight rock salt.

First the criticism is that the 'natural' aquarium will have too much salt if we use baking soda, then suddenly the 'proof' everyone in all forums, all literature are wrong is that water changes do not kill Discus. If we are doing weekly water changes what is the 'big' risk with baking soda?

I still do not see how, unless every chemist is a liar, that distilled water which the lying chemists claim, have an affinity for change, yes the pH may be 7, but it does not stay that way.

Distilled water is by itself dangerous, unless reconstituted and if that reconstitution does not include some carbonate hardness... then it will be greatly influenced by the products of biologic activity, the soils, by a number of sources.

i should not have answered. I will refrain. back to TPT.

stupidly yours,
Joe

 

I agree , i have a low Kh near zero but isn´t zero.

I disagree, with EI applied to non CO2 tanks will generate some trouble with some species of fish, since the waters changes are made rarely the ph will go down and will not rise again.

I agree the ph will always during the day go between 6 and 7 for example

Well, baking soda could be more lethal but what can i do?

 

Hi ismenio,

If you really like to test increaing the KH, despite what you were told, you can add CaCO3 or MgCO3, far better than baking soda in my opinon.

About your KH/PH/CO2 table conclusions, we all know and claim that this table should never be used. It doesn't account for anything but KH and CO2 in the PH balance, which is wrong in our aquariums.

Unless you have a very low PH, 4-5, with fish originating from hard waters, I don't think you should be concerned. If you're concerned about fish health, focus on the GH/conductivity ranges to avoid extreme limits of the specie and perfect maintenance. Tanks with no water changes or few water changes, will never make fish live for its life expectency like with regular water changes

 

Thanks jonny_ftm

I will start with the waters changes all weeks to avoid the use of backing soda, i think it´s the best for my problems.

Thanks to all that help me.

PS: One day i will try maintain discus and angel fish in ph of 8 side by side with African Cichlid.