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Re: H2SO4

> Date: Mon, 23 Apr 2001 00:24:47 -0700 (PDT)
> From: Anh Thach <thanh at redhat_ccc.cccd.edu>
> Subject: I want to buy large quantity of Sulfuric Acid.
> How do you guys lower the pH of a 60 gallons tank? I use R.O water but the
> pH is still high like 7.2-7.4, and if I want to lower it to 6.6-6.8, that
> would take a lot of pH Down. A bottle of pH Down cost $4.50. Is there a
> cheaper alternative such as buying large quantity of H2SO4? Where to buy?
> Thanks for any help.

Why do you need low pH? For plants or something else?

For plants:
Add CO2 for plants if you need lower CO2. Don't use RO or acids or any thing
just the CO2 gas according to the pH/KH/CO2 table. There's almost never a
reason to lower your pH with H2SO4 (doesn't this seem a little radical just
to keep some plants? THINK about it. Do normal folks do this?). My pH out of
the tap is very high and my hardness is way up there(410-450ppm). Plants
don't care about those but they do care about CO2 content so if you need to
lower your pH to get it matched up nicely with the pH/KH/CO2 chart add nice
reasonably safe CO2 not H2SO4 which is some of the nastiest stuff out there.
Dosing CO2 is far easier and more practical than any H2SO4 addition idea you
have in mind. 

Needing a lot of pH down:
But if it's RO there's no buffer left in the water anyway. Adding even a
trace amount of acid (most acids will work) will drop the pH
severely.........you can kill your fish. Even a weak acid like adding the
CO2 gas to water will knock the pH way down even in small amounts if there's
nothing left in the water. Your pH will be all over the place and hard to
control then. It will be difficult to hit a set pH. Not sure why you need
any of this. It's not for the plants ........I can promise you that. Not a
good place for anything really in the long term.

 Plants and many fish need the hardness that the RO removes.........
Why remove something then add it back? Got extra cash you don't know what to
do with? Like extra work? Like something that's more complex and easier to
mess up? To each their own but relative to plants it's a waste. Please send
me the cash instead:)

Plants do not need reconstituted RO/DI water nor any acid added to the tap
or RO/DI etc. It's myth. You can do it without CO2 also. Or if there's high
NO3, PO4 etc in the tap. There's  almost always a way around using RO/DI for
planted tanks. Of course if you are trying bred some super soft water fish
but still want a nice planted tank there's always trade offs(plants won't be
too happy) but you certainly do not need any of this mumbo for nice plants.
They actually like the hardness, PO4 etc. Fish are not too picky about it

You need H2SO4 for something else besides plants? You can use HCl also, get
it a pool supply places for cheap or Home Depot/Orchard's etc. Likely much
cheaper than any H2SO4. If money is a concern that is....but you bought an
RO....you can buy that, you can buy CO2. pH down is H3PO4. You want to add
PO4 but not CO2? HCl is better.
Personally I'd would never do it. CO2 only here. This is the only acid

Tom Barr