Re: [APD] Lowering KH, Which Is Better: RO Unit or Strong Acid?

[Dave Wilson <aqua_green at bigpond.com>]

> 
> Is using the acid THAT complicated and involved?  That's not a
> rhetorical question.  I seriously am curious.

I used to work in Austrtalias largest fresh water public aquarium up to a
few years ago.   We used to make batches of water lowering the alkalinity
down to 55 ppm from 175 ppm using hydrachloric acid.   The water came from a
bore (US call them wells) that had a pH of 7.5 then after being in the
aquariums for a while went up to over 9.2 after CO2 degassing.   This was
not very good for most of the fish.    The water for smaller aquariums was
mixed in 2000 litres batches.   We put small amounts of acid in initially
stabalising the pH until it was determined the alkalinity and pH level we
wanted and the amount of HCl needed.

When you added the required anmount of HCl in one step the pH would frop
down to about 3 then rise up over the next few hours to 7.

The main display aquarium was 400,000 litres and had a dosing pump with auto
make up water top up straight from the bore.   Each day a diver would clean
sediment from the bottom of the aquarium.   The top up water would get the
dosing pump operating very quickly.    It was a big dosing pump and held the
pH at 7.77 at all times as long as the pH probe was correctly calibrated.

If you are going to make up water with a lower pH using acid make it up a
few days before you need it in a big container with vigorous aeration.

Cheers
Dave

PS if you are ever in Darwin don¹t miss visiting the Territory Wildlife Park
aquarium that displays all the local fishes and aquatic life.   It has very
large planted aquaria.


_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo/aquatic-plants