I accidentally adjusted the pH of my water-change water to 14dKh....What now?

[hansnfrans]

Since I used baking soda to raise the alkalinity of my water-change water, I was thinking that maybe I can bring the alkalinity back down with an acid... :confused:

Details:
The total water-change water affected is 55gal.

I need to bring the alkalinity down to around 9 or 10 dKh.

This water-change water will then be used on a 75gal system at an alkalinity of 9.5 dKh.



What do I do at this point?

Thanks.

[bertoni]

If any animals are showing signs of trouble, some water changes should help. Otherwise, I'd just wait. A mineral acid could be added to reduce alkalinity, but they are dangerous to handle and overdosing could cause a lot of harm.

[hansnfrans]

bertoni - actually this problem occurred in my water change container before I did a water change and I would like to remedy this before doing the water change on my 75gal SPS system.

[Randy Holmes-Farley]

The boost to tank alkalinity is quite small for a 10% water change. A 10% change with 14 dKH to an 8 dKH tank will only boost it to 8.6 dKH. So I'd use it without messing with it.

[hansnfrans]

Randy - I was hoping to do a 30% water change, but it is looking like it'll just be easier to do a few 10% changes over a 3-4 days. Thank you for that calculation ("A 10% change with 14 dKH to an 8 dKH tank will only boost it to 8.6 dKH")

BTW: How did you calculate that?

[Bonebrake]

(10% x 14 dKH) + (90% x 8 dKH)

= (0.1 x 14 dKH) + (0.9 x 8 dKH)

= 8.6 dKH

A 30% change all at once would be:

(30% x 14 dKH) + (70% x 8 dKH)

= (0.3 x 14 dKH) + (0.7 x 8 dKH)

= 9.8 dKH

Doing a full 30% change all at once is really not a big deal and will not hurt anything. Matching salinity and temperature is probably the most important thing when doing large water changes. Small water changes (10% or less) have to be wildly off on parameters to make any kind of impact.

[Randy Holmes-Farley]

:thumbsup:

Good luck. :)

[hansnfrans]

Thanks guys! :)