Re: Muriatic Acid - HCL 34%

[Wright Huntley <jwwiii at pacbell_net>]

Tranquility Base wrote:


> 
> I usually adjust a 20 gal fish tank (actually about 17 gal) at a time from
> pH 8.3 to 7.3. I know that I will have to tweak the recipe some but does
> anybody have a clue about how much acid I should start with. For example 1
> ml or 1 cup?


Tiny drops of diluted acid, and a looooong wait before measuring the final 
results. Seriously, RJ, don't do it.


I'm curious as to why you should want to do this. We have known for years 
that killies don't particularly feel/taste pH (see Scheel's _Atlas..._ for 
example). The pH mythology has been propagated by the LFS as it sells a lot 
of test kits, and many of them *have* honestly confused the effects of 
osmotic shock with ph shock. [Since harder water is often higher pH, putting 
fish in lower tds (lower pH) water can easily cause major gill and skin 
damage, followed by outbreaks of Ich or Velvet if not immediate death.]

Adding Muriatic Acid to your tank water will cause pH to drop, but it should 
quickly bounce back. Add some more, and it will drop again, but will bounce 
back again. What it is doing is destroying the alkalinity -- buffering -- in 
your tank water (aka KH). When you have bounced the pH enough times, it will 
eventually stay down, but now your pH may easily "crash" which can make any 
nitrites in your tank as deadly as any ammonia might have been at the higher pH.

IMHO, the way to do it is leave the pH alone and be darned sure you have no 
ammonia/nitrite in your tank. Plants, an active biofilter, and adequate 
water changes do that rather easily. If your tds (not pH) is too high, then 
dilute with RO or rain water.

Your sodium biphosphate was providing a different buffer (from the calcium 
bicarbonate complex of normal water) at a lower pH, which is quite different 
from what a strong acid can do.

Unfortunately, many folks felt that phosphate was a limiting nutrient for 
algae, so it probably promoted algae growth in your tanks. [That's why it is 
banned in detergents, in many areas. It was causing algae blooms in lakes 
and ponds.] Stores rarely carry it, now that word of the algae problem is 
well spread in the hobby.

The LFS liked that algae-promoting side-effect for it sold a lot of Asiatic 
Scale Suckers (mislabeled as Chinese Algae Eaters) and those created a good 
turnover in other fish, back in the days when fish were a profit item. :-(

Wright


-- 
Wright Huntley -- 650 843-1240 -- 866 Clara Dr. Palo Alto CA 94303

Ask of politicians the ends for which laws were originally designed, and 
they will answer that laws were designed as a protection for the poor and 
weak (...) but surely no pretence can be so ridiculous(...). -- Edmund 
Burke, A Vindication of Natural Society, 1756


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