pH buffer

[RonWill]

Hi all,

My Chemistry sucks big time but what's available to the hobbyist for buffering pH at about neutral, ie. pH7, without hardening the water excessively?

I'm experiencing something for the first time and not sure if it was pH related, with a large piece of driftwood.

Fresh woods, as we all know releases tannin, which acidify the water. Fishes with low tolerance for acidic waters, like black mollies and guppies, will show signs of distress. Plants in general are more forgiving.

But... in the tank I'm seasoning the driftwood, the anubias are 'burning out' and dying. Some look like they were blanched in hot water!

I did a pH check with some Merck pH test strips and the color match was about pH5!

Almost all the snails in that tank shows high calcium deficiency with paper-thin shells that literally break at a light touch... that's not right and I do have some pieces of coral chips.

After a 80% water change, pH climbs back up to 7 but the question now is; what can I use/add to buffer/stabilize the pH from crashing further down?

[FC]

Ronnie,

Sodium Bicarbonate (baking soda) can be used to buffer PH without hardening the water. Add (by the teaspoons) till you get KH of 3~6.

Coral chips are my favourite, it adds Ca (increase hardness of about 2~3 degree) and buffer (increase KH of about 2). To be effective, they have to be placed in the filter where the water current is because it is a slow dissolver but it provide a natural and mild buffer.

[Green Baron]

More coral chips ?

[howler]

Hello
It`s much better if you use KHCO3 (Potasium bicarbonate) instead of the baking soda. You´ll be adding an important ion for you´re plants such as K+ while you raise the KH value. The disadvantage is that it´s not as cheap as baking soda. On the other hand, by using baking soda you´ll increase the salinity too, and some times it´s not the best thing to do.

If you need a higher GH as well, try using some Epson salt(MgSO4) too. Your plants need not only Ca+2 but Mg+2 too. The relation between them should be 3:1 Ca:Mg. This salt is really cheap so it´s not wise not to provide your plants some Mg+2.

[RonWill]

Thanks Juan for the info and putting the chemical names besides the 'symbol', otherwise I'd have to 'google' for every item I see.

If I understand you correctly, KHCO³ (Potasium bicarbonate) will buffer pH without hardening the water or increasing salinity? I suppose I could get some from the chemical suppliers or LFS selling PMDD. May be more costly but it's a price that chemistry-handicapped people have to pay

For the dosage, how many grams of KHCO³ and MgSO4 (Magnesium sulphate?) would I need for a 24"L x 12"W x 16"H tank (approx 76 Litres or 20 US Gal)?

BTW, I searched for "Ca+2" and "Mg+2", but don't quite understand. What is this two items? (please, in layman terms, if possible).

[howler]

Hi Ron,

If I understand you correctly, KHCO³ (Potasium bicarbonate) will buffer pH without hardening the water or increasing salinity?

That´s right. The water hardness is caused only by Ca+2(calcium) and Mg+2(Magnesium) and the salinity mainly by Na+(sodium) and Cl-(chlorine).
The buffering properties are caused exclusively by the bicarbonate anion.

For the dosage, how many grams of KHCO³ and MgSO4 (Magnesium sulphate?) would I need for a 24"L x 12"W x 16"H tank (approx 76 Litres or 20 US Gal)?

Right again, it is magnesium sulfate.
You don´t say which is your initial KH, I need to know in order to work out the exact dosage. Anyway, I don´t think it´s really worth the trouble, for you I mean. The CO2(carbon dioxide) has a complex equilibrium in water, therefore the KH is unconstant. You´ll be better of using the "trial and error" method. Just add a litlle bit, measure and add more if needed. It´s a real mess the first time you do it but you´ll do it much quicker next time.
If you wish not to do it this way, you´ll have to tell me your initial KH to work out the dosage and even then if you don´t have the right apparatus it´ll be of no use.

BTW, I searched for "Ca+2" and "Mg+2", but don't quite understand. What is this two items? (please, in layman terms, if possible).

Ca is calcium and Mg is magnesium. The (+n) means it´s a ion, a cation to be precise because it´s a positive value. These metals appear as ions in water.

I hope this will be of some use to you.

[discusdave]

Ronwill,
You are dealing with two issues in your tank, it appears: improper management of GH which results in the snail shell problems, and improper management of KH, which results in too low a pH. My chemistry is not the best, but we planted tank hobbyists deal with two main chemical parameters regarding chemical additions to our water: GH and KH.

GH is General Hardness and KH is Carbonate Hardness. Think of GH as all the dissolved minerals in the water not affecting pH (calcium and magnesium ions), and think of KH as the minerals that affect pH (bicarbonate and carbonate ions).

First KH:
An aquarium will have a tendency to drop in pH (acidify) over time because of the biological processes that happen with fish and plants. Carbonate Hardness (KH) is the water's ability to buffer, or resist the acidification process that happens in a tank over time. The Carbonate Buffers (KH) try to keep the pH stable as the tank water acidifies. If you have too low a KH (0-1 or 2), then you don't have enough carbonate buffers to resist the fall in pH and you can end up with a pH of 5, like you did.

Most planted tank keepers in the US like to keep their KH at 3 or more. I try to keep mine at 4. This gives the tank water stability, and allows the addition of CO2 (which acidifys the water) without crashing the pH. I use a Seachem product called Alkaline Buffer, which specifically builds the KH of the water. Other products are available, but Alkaline Buffer was designed specifically for building KH.

You need a decent test kit to monitor the KH. I use Tetra, which is inexpensive, but has worked well for me for years.

Now GH:

A lack of General Hardness is the cause of your snail's brittle shells. If there is not enough calcium in the water, their shells are thin and brittle, or they have holes in them. General hardness assists in fish's osmoregulatory functions as well.

I use another Seachem product, Equilibrium, to build the GH of my tank water. Again, it is specificaly designed to build GH without affecting pH.

I use a Tetra GH test kit to measure GH as well.

My tap water comes out with a GH/KH less than one, so I need to use GH and KH builders.

I refer you to this great article that explains the relationship between GH/KH/pH in the aquarium:

http://www.drhelm.com/aquarium/chemistry.html

Hope this helps.

[howler]

Hi all,
I´ve not much to argue with discusdave, I think we pretty much say exactly the same. However, i´d like to add a couple of things:

- you shouldn´t always relly on the comercial buffers for aquariums. On one hand some are a real rip of. Believe me, I´ve seen more than once how they sell just baking soda with a flashy name like "ultimate water buffer" for a much bigger price than it´s really worth. And on the other hand, there is the other kind of comercial buffers , the ones that use phosfates to do so. This sometimes it´s not the best thing to do.

- why buy a Mg/Ca mix to increase the GH value for an incredible high price when you can prepare the same thing your self for a few €??. The MgSO4 cost 10€/25kg and calcium salts are jus as cheap.

[shortman]

- why buy a Mg/Ca mix to increase the GH value for an incredible high price when you can prepare the same thing your self for a few €??.

Ronnie,

I agreed with Howler. Infact I have the Mg2S04 and can pass it to you over the weekends. I just did some test after reading your thread at home.

I put a handful amount of coral chips into my external filter tray and in two hours I raise the PH from 6.2 to 7. And I notice that when the high water pressure pass through the coral chips tray it acts like a calcium reactor.

And now I have problem to low it down. :-(

[discusdave]

Regarding the use of commercial buffers. My response was in no way an endorsement of any one specific method to buffer. You can make your own. The URL I gave gives suggestions of non commercial type GH/KH buffers.

I use Seachem products by choice, as they have a reputation for high quality and are designed with the aquarium environment in mind. Their KH builder, Alkaline Buffer, is non phosphate, and their GH builder, Equilibrium, is designed specifically for the planted tank and uses no sodium or chloride.

Over the years, I have found, at least with these two products, they are consistent in their manufacture, and they always do what they say they will.

[howler]

I´ve not much to argue with discusdave, I think we pretty much say exactly the same. However, i´d like to add a couple of things

Discusdave, all I did was add a few things, I never intended to ofend you, sorry if I did.
All I said were a few facts of comercial mixtures. Do you know the composition of of the Seachem buffer?..if I´m not too wrong I think it´s mainly NaHCO3(baking soda)

[RonWill]

Dear all,

Thanks for the details and please excuse me if I seem a little quiet and slow in response. I'm still on a learning curve despite having maintained a planted setup a few years ago. Never was much of a number cruncher then, more an observer, noting changes and behaviour of the critters instead.

To tide over the low calcium levels, I've added clean crushed shells from about 10 eggs, one-eighth of a 450mg calcium tablet and a light sprinkle of gypsum (plaster of paris), which I remember contains calcium bicarbonate. I'm guessing that upping the hardness will temporarily hold the pH stable. These were what I used to use and apologies if my haphazard approach runs against 'calculated methods'.

I'll be meeting fellow forumers at a LFS later this evening, and they have PMDD stuffs there. I'll browse through and see what's available.

Since Epson salt is MgSO4 (and cheaper), I'll probably go with that. BTW, what is the consequence of MgSO4 overdose? I vaguely remember that excess of some nutrient will block the uptake of another (only problem is, I can't recall which blocks what ).

Presently, I'm using TMG but not regularly, and lesser than half the recommended dosage, since a majority of my plants are low-light. These, I understand, have slower nutrient uptake.

Will try to upload a pic of the tank in question, even though I'm 'cycling' it and house only a few fishes and shrimps. It will, in time, be a permanent setup for my Aphyosemion BIT 'Ijebu Ode'... a killifish, of course :wink:

Will re-read what's written so far and digest it slowly. Thanks again!

[discusdave]

Howler,
No offense taken. However, the composition of the Seachem products is more than just baking soda.

Seachem Alkaline Buffer (KH) is composed of Sodium bicarbonate (baking soda), potasssium bicarbonate, magnesium, and "other" bicarbonate salts, per the label.

The analysis of Equilibrium (GH) is 23% soluble Potash (K2O), 19.5% Potassium (K), 8.06% Calcium (Ca), 2.41% magnesium (Mg), 0.11% Iron (Fe), and 0.06% Manganese (Mn).

Seachem attempts to address the needs of the plants in these products by making them out of ingredients the plants can use.

I prefer the convenience of these pre-made products. If Alkaline Buffer was only baking soda, I'd buy baking soda and save some money, but it is not. Both products are composed of beneficial elements (K,Mg,Mn,Fe,Ca) that are available to the plants when in solution.

You can use baking soda only to build the KH, but I'd rather use bicarbonate salts that have benefits for the plants, as well.

Same thing for building the GH

[RonWill]

Hi folks,

While meeting up with fellow members who're collecting their killie-egg orders, I picked up a PMDD kit from the LFS. It seems to have everything needed and will post further details/pic of it later. What's pretty obvious would be... what am I to do with it? (quickly scurrying into flame-retardant suit )

Another thing that struck me this morning, while sprinkling the weekly teaspoon of dolomite lime into my vermiculture, was whether the lime can be used as a buffer? Afterall, it's used to prevent the worm bedding from becoming too acidic. Any opinions/suggestions appreciated.

[FC]

What's pretty obvious would be... what am I to do with it? (quickly scurrying into flame-retardant suit )
whether the lime can be used as a buffer? Afterall, it's used to prevent the worm bedding from becoming too acidic.

Yes, you ought to be and would be flamed! No question about it.

Use of dolomite
I have a can of dolomite sitting still in my tank's cabinet. It is lime used commonly for carpet grass to buffer acid rain. It is CaMgCO3, in another words, adding it to water would give you Ca, Mg (1:1) and CO3 that would provide PH buffer. For this, do not place them in filter, sprinkle them over the gravel bed. They would dissolve over a long time. It has the same stable CO3 charactistic like coral chip in that it dissolve/response according PH fluctuation - a natural mild buffer agent.
For your 3 footer acid prone tank, start with 1 table spoon. Compare the PH after a week. The PH should stabilise after 1~2 weeks. Add another table spoon should you need higher PH (less acidic). That 2 spoons would last you at least 6 months of fornightly water change, if you do.

Note: after adding, it may cloud the water a little but would clear up within an hour

[hammy]

Hi Freddy, so which do you prefer? Coral chips or dolomite? And why?

[RonWill]

It is CaMgCO3, in another words, adding it to water would give you Ca, Mg (1:1) and CO3 that would provide PH buffer.

Freddy, a few more questions before I get toasted...

If dolomite lime is Ca, Mg and CO³, does the carbonate (bicarbonate??) comes from the calcium or magnesium (or it doesn't matter?)

For your 3 footer acid prone tank, start with 1 table spoon.

It's a 2 footer (24"L x 12"W x 18"H). Will 1 teaspoon be enough and in the event of overdose, what are the visible consequences?

I don't mind the initial clouding but since you're also using dolomite, how do the fishes react when you sprinkle?

There's one observation I'd like to add. When I drop a one-eighth cut of Ca tablet into the tank, the snails will gather and feast on it. Why do these snails think it's food?

[FC]

Dear Selwyn,

It depends on what you wish to get out of it. For Ronnie, he is looking for PH buffer, so the choices are more.

If dolomite lime is Ca, Mg and CO³, does the carbonate (bicarbonate??) comes from the calcium or magnesium (or it doesn't matter?)

Dear Ronnie,
It is carbonate, that's why it does not dissolve readily when compared to bicarbonate. That's why it is a mild buffer. They, Ca, Mg & CO3, all bind together.

It's a 2 footer (24"L x 12"W x 18"H). Will 1 teaspoon be enough and in the event of overdose, what are the visible consequences?

The tank looks bigger than I thought. As a start, try 2~3 teaspoons instead. They are very slow "dissolver" and react/dissolve according to the acidity, when PH approaches 7, they will virtually stop dissolving. 2~3 teaspoons are very safe.

I don't mind the initial clouding but since you're also using dolomite, how do the fishes react when you sprinkle?

They first thought they were my food pallets but did not eat them at all. I guess they smell first.

When I drop a one-eighth cut of Ca tablet into the tank, the snails will gather and feast on it. Why do these snails think it's food?

I can't comment on this. Just a wild thought, maybe just like horses lick on salt plate (as they knew that they lack salts), the snail did that because the water is too soft? Don't flame me, take this as an equalizer

[RonWill]

Hi Folks,
Here are some pics of the PMDD kit I bought. Quite hesitant to start dosing without idea of dosage.

The tank looks bigger than I thought.

Freddy, are we talking about the same tank

http://www.angelfire.com/journal2/fi...m#OceanFree2ft
The pic was taken May 10th but the driftwood is still leaching tannin. Will post a updated pic when time allows.

...the snail did that because the water is too soft? Don't flame me, take this as an equalizer

Judging from the white snail poo, I know they ate some of it and yes, the score is now nil/nil :wink:

[FC]

Hi Folks,
the PMDD kit I bought

You are into trouble - they looks poisoneous. I have them too, for some reasons, they like it.
Let me know you email, I will send the formula on how to administer them.

Freddy, are we talking about the same tank

Yes, now you see how good my guessetimation is.