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I have been doing alot of reading regard aquaria and the sort. I have been raising liverbearer for a while now and am studying to upgrade to a heavy plant tank. In my research i came across a question that has puzzled me. so here goes.

In so many source i hear especially forums that if the ph need s to be altered one shouldnt every, never ever use chemicals. instead to raise the ph one should use peat..its always puzzled me. Why cant i raise ph with aquarium products i.e. ph down?

p.s. i realize the the ph will go up with a co2 tank. its really just a question that has been bugging me for a while.

thanx.

I think probably it's because for one thing, it's easy to overdo it on chemicals. For another, it only works until you do the next water change, then obviously you have to add chemicals again. This will result in fluctuating pH all the time. If you add something to the filtration you will have a stable system.

P.S. I think you are referring to bringing pH down, not raising it.

The trouble with chemicals/powders it can be extremly difficult to get the exact proportions correct when adjusting the PH. It takes a lot of experience to get it correct each time. If the PH is out too far (High or Low) the chemicals must be added gradually and tested at each adjustment.

You can add small amounts of natural products in panty to a filter and this will keep the PH to the desired reading you require.

All I ever do is add a PH buffer at every water change this give me a good reading all the time unless there is a another problem

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Keith

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Hi,
Peat will release organic acids into the tank and lower
the pH as will the injection of CO2. The amount of change
depends upon the buffering capability of the water. That
is termed the KH, or Carbonate Hardness, of the water.

Generally speaking Livebearers prefer water with a little
calcium and magnesium in their water, in-other-words, a
slightly higher pH from 7.5 to 8.0.

One can easily shift the pH in either direction naturally,
or with chemicals. Many of us prefer to do it naturally
through the use of peat, CO2 injection, or in the other
direction through the use of a carbonate material such as
crushed coral, crushed dolomite, crushed limestone, or
crushed oyster shells.

You and also use products such as pH UP or pH Down which
is available from your LFS or from any swimming pool/hot tub
supply company.

When shifting the pH, always do it slowly as it directly
impacts the fish and can stress the fish's metabolism.
Never shift more than "A" point in 24 hours, and if shifting
from say, 7 to 8, or 7 to 6, do it over a couple of weeks to
be safe. Some fish are more sensitive than others.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

swimming pool/hot tub supply company.

If you decide to go that route, kantankerousmind, just be warned that the stuff meant for pools/spas is POTENT -- it is usually just pure chemical. The pH plus we sell at my store is 100% sodium carbonate powder. Similarly, the pH minus is 100% sodium hydrogen sulfate powder. You really have to be careful with the doses. If you're not afraid of doing a little chemistry calculating, though, you can save yourself a lot of money. 9 pounds of sodium carbonate sells for about 14 bucks, and that will keep you stocked for the rest of your natural life if you are only using it for aquariums -- unless you're running thousands of gallons of reef or mbuna tanks, in which case you're already rich enough to not have to worry about saving some money.

The stuff you get at the LFS is just a weak aqueous solution of (most likely) the same compounds, and you pay much more per unit.

Baking soda is all I use to bring my pH and KH up. Epsom salts brings up GH. I add 1/4 tsp each per bucket when I do a water change and it keeps it roughly at the same level, and it's cheap. I've never had to bring pH down before.

Most natural methods continually release the acid or buffer that keeps the water at the correct ph. Most chemicals wear out quickly. PH down burns through the kh, lowers the ph, and then if not dosed again frequently runs out and the kh buffers the water so the ph bounces back up to what it was. With peat the change is gradual because it slowly leaches out tannic acid and steady because it continually gives off the same amount. You can still use too much peat but you'll notice the problem sooner since it may take several days to end up with too low of ph. With chemicals the ph may drop instantly far too low. You have to test constantly and may be required to dose it twice daily or at least daily. Peat can last weeks before it has to be changed depending how much your trying to change the ph. Methods that raise the ph are even more permanent. You can stick a chunk of limestone in a tank and never touch it again. Crushed coral can last weeks to months and baking soda is only added when you do a water change.

Hi,
If your goal is to increase your pH, then Baking Soda is
not the way to go. Baking Soda is a carbonate and will
increase your Carbonate Hardness, which incidentally
affects the pH.

Likewise, Epsom Salts does not truly increase your
General Hardness (GH). It contains Magnesium which is only
one component of General Hardness. The best way to
increase your pH and GH is to add crushed carbonates such
as crushed limestone, crushed dolomite, or crushed oyster
shells. Crushed coral will work, but it is primarily
Calcium Carbonate and does not contain any more than trace
amounts of Magnesium, etc.

Also, pH Up and pH Down are not permanent "fixes" and
require dosing with each water change.


Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

In most cases PH down will require far more frequent dosage than waiting for a water change. The only person I talked to that uses it successfully doses daily.

Wouldn't adding calcium carbonate be increasing the gh the same as epsom salt? Considering the fact that gh is both a measure of magnesium and calcium each one would only be half. There isn't any magnesium in CaCO3. Even then that's not the total mineral content of the water but only a measure of the 2 most common so you could say even if we added both we still aren't truly raising the entire GH.

Wouldn't baking soda eventually impact ph? You can't just raise the kh forever without something happening and the fact that additions of baking soda stop the ph from dropping shows it does have an effect. I would think eventually you would cause an increase in ph if you kept adding excess baking soda. Not that I have any water around to test it on since you can't really get a higher ph than my wellwater is already at.

Wouldn't adding calcium carbonate be increasing the gh the same as epsom salt? Considering the fact that gh is both a measure of magnesium and calcium each one would only be half. There isn't any magnesium in CaCO3. Even then that's not the total mineral content of the water but only a measure of the 2 most common so you could say even if we added both we still aren't truly raising the entire GH.

That's why Frank suggested dolomite (chemical formula CaMg(CO3)2). In any event, I'd feel more comfortable adding a carbonate than a sulfate. For whatever reason, though, GH is measured as mg/L CaCO3, but I never knew why. Can anyone explain that to me?

Wouldn't baking soda eventually impact ph? You can't just raise the kh forever without something happening and the fact that additions of baking soda stop the ph from dropping shows it does have an effect. I would think eventually you would cause an increase in ph if you kept adding excess baking soda.

With an acidic pH, NaHCO3 will work fine for raising pH via HCO3- + H+ --> H2CO3 --> H20 + CO2. With a basic pH, though, NaHCO3 will only raise the pH a little bit. Since NaHCO3 is more of a buffer at higher pHs (via the HCO3- anion, which can either pick up an acidic H or give up its remaining H in order to maintain pH) than an actual basic salt (although, to be fair, it is a weakly basic salt because it is formed from the incomplete neutralization of the diprotic weak acid H2CO3 and the monofunctional strong base NaOH (H2CO3 + NaOH --> NaHCO3 + H20)) , it has a much larger effect on alkalinity than on pH. The thing is, though, that as you add more of the HCO3 anion, it tends to suck up any available hydrogen ions in the water -- but since water only self-ionizes on the order of one molecule per 10^14 molecules, there's not much free H+ once the pH gets above 7 and the HCO3 is more likely to give off its H (to form water via HCO3- + OH- --> CO3-- + H20) rather than pick one up because the concentration of OH- would be greater than H+. As a result, pH is being stabilized as any new OH- that is formed is very quickly converted to water. OH- is a stronger base than CO3--, so it has no trouble plucking the proton off of HCO3-. That, in a nutshell, is how alkalinity works. When alkalinity is high, there are a heck of a lot of buffer molecules in the tank which can accept or donate protons as needed to maintain a steady pH, resulting in an equilibrium between protons, hydroxides, and buffer molecules. When alkalinity is low, there are very few buffer molecules and they get used up very fast, resulting in rapid and large pH swings from excess protons or hydroxides, although it is a difficult thing to achieve a high pH and a low alkalinity in a tank.

Wow, that was a long and rambling response, and I could be way off-base, but I thought it sounded pretty good. At least in my head, where anything sounds good.

Edit: More info and I bolded what I thought to be the most relevant part of that whole spiel.

I should have taken more chemistry. I was really good at it and finished my highschool class with over 100% of the points. I just never even considered taking it in college. It would also have been useful when I get in arguments with my sister(chemical engineer).

How you raise/lower your Ph should also depend on the source water. If your water is low KH and hard (medium high) GH like mine, you want to raise the KH to raise the Ph. To lower the Ph, you want to make sure the method used lowers the GH and not the KH. If you KH is too low, your Ph is more likely to swing up and down with little change in chemistry. The reason it's called a buffer.

Also, if your planning to use CO2, keeping the KH a little higher will keep your Ph from swinging to much while the lights are turning off and on. The plants use CO2 when lights are on (PH goes up) and creates it when off (Ph goes down). Best route is to turn the CO2 off at night or use a CO2 controller, unless you are using DIY 2 liter bottle method w/ yeast and sugar which will makes it hard to get very much co2 into the water anyway. Should keep close eye on water parameters in beginning.

Wouldn't baking soda eventually impact ph? You can't just raise the kh forever without something happening and the fact that additions of baking soda stop the ph from dropping shows it does have an effect. I would think eventually you would cause an increase in ph if you kept adding excess baking soda. Not that I have any water around to test it on since you can't really get a higher ph than my wellwater is already at.

As far as I know, Baking soda will raise the Ph gradually up to 8.0-8.2 then stop no matter how much you add. I have experimented with this with a cup of my tap water before and it appears to be true. If I understood why I would be smart. That might be what all that chemistry stuff says above. I wouldn't know.

holy smokes! I had no idea the question would result in so much valuable information...
everyone input was so greatit has given yet another basis for learning more. so i think that i will start looking for dolomite..

maybe i should post this next question in another post but i read in an aquarium book "survival guide" or so.. that only aquarium grade rocks will do as the risk of limestone presence is a concern. no the book never spoke of why (ph or anything) but it lead the reader to think that limeston would be FATAALLLL (eerree voice)

but it means that my livebearer could have had better water maybe some one could speculate if the only reason the book said to avioid limestone was because it affect PH.

Hi,
The addition of any carbonate rock (Limestone, Dolomite,
etc.) will harden the water (raise the GH) and as well
as increase the pH into the "8.x" range.
How fast this occurs depends upon the KH of the water,
how much of the rock is added, and if it is one big rock
or crushed rock.

As far as being fatal is concerned, it depends upon the
species of the fish and how fast the change occurs.
Some would love the harder water (African Rifts, and some
live bearers.)
Some would acclimate to it as it changed (many of the
cichlids) others (many of the Tetras) would die.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Any chance this thread could be made "sticky" so I can refer to it more easily in future?