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Re: Dosing HCL

Len Kutz writes:


> I recently purchased some 20% HCL and have been dosing a small amount every
> night trying to lower the ph of my tank.  It is a 75g tank with tap water
> that is about 8.25 ph, 100+ ppm GH and 120+ ppm KH.  For the past 4 nights
> I've added 15-20 drops of HCL to the sump.  Every night I measure the ph
> before putting in the HCL and about 2 hours afterwards.  Every evening
> before putting in the HCL the ph has been up to or very close to 8.25, but
> after adding the HCL the ph drops to about 8.  I'm concerned about dropping
> the ph to quickly, but I didn't expect the ph to keep going back up so much.
> Am I doing something wrong or is it the buffering of the hard water causing
> this?

This is the buffering of the 120 ppm KH.  Test your KH after 4 days of doing 
this and you will realize that you ARE making progress, but not very quickly 
at this pace.

>  Should I put in more HCL?  Any suggestions would be appreciated.

It's not the drop in pH that is actually dangerous, it is when the pH crosses 
below 7.0 and your dissolved nitrites suddenly become toxic.  When pH rises 
from below 7.0 to above 7.0, ammonia becomes a problem.


   I've been very cautious doing this and so far none of the fish or plants
> show any signs of problems.
> 

A better solution might be to figure out how much acidit takes to permanently 
change the pH to your target level in a bucket of water.  Then prepare about 
ten or fifteen gallons of water down to a pH below the target level.  Once it 
is stable, use it to do a partial water change.  After several changes over a 
couple weeks, you will reach your target pH.  Then prepare all of your water 
for changes a day or two in advance.

Another approach to use is to use RO or DI water mixed with tap water.  In 
terms of a healthy tank, this is a little more expensive, but worth it.  My 
water has about the same hardness, and a pH of 8.0.  By simply using 80% DI 
and 20% tap, I get a pH of 6.2, which is ideal for most of my fish.

Before going to the effort of changing your water chemistry, decide for sure 
why you are changing it and whether you really even need to.

Bob Dixon
Cichlid Trader List Administrator        o
http://cichlidtrader.listbot.com               0
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