pH swing - something to worry about?

[kolosy]

here's my pH behavior over the course of about 24 hours. The pH falloff begins when my MHs go out. the spike in the middle is when i started dripping kent two part part b (buffer).

Is that level of swing an issue? should i slow the drip to try and make it last through the trough?

i do have a reverse-light cycle fuge w/ chaeto.

http://www.kolosy.com/stuff/aquarium/ph.jpg

[joshkennedy07]

Looks ok. I run my PH a little higher, 8.25 - 8.38. I have been told PH swings of 0.2 are acceptable.

[goreefer]

A swing of the pH is normal, but your's looks a little low.
The other thing to do is to drip you buffer when the lights are off. If you look at your graph the time to drip is between 2:00 am and 8:00 am.
That will keep the pH at a more constant level.

[kolosy]

hm. my problem with an acceptable swing range is that the pH scale is logarithmic, so the difference between 8.3 and 8.5 is more significant than 8.1 and 8.3.

oh well...

[kolosy]

are there automatic dosers for that? and how big of a deal is what i'm seeing? again, like you said - some pH swing is normal.

[crvz]

perfectly normal, I wouldnt worry about it.

[goreefer]

"are there automatic dosers for that? "
Yes,
You can set your AC3 up to only turn on the ATO or Doser between any set time, or as I have done is to only allow my ATO to come on when the pH is below 8.2 and shut off when it gets to 8.4. It works really well. I use an ACjr, but both will work the same way.
I top off with Mrs Wages mixed into RODI.

[spw4949]

<a href=showthread.php?s=&postid=13636991#post13636991 target=_blank>Originally posted</a> by crvz
perfectly normal, I wouldnt worry about it.

Agreed.

[kolosy]

<a href=showthread.php?s=&postid=13637047#post13637047 target=_blank>Originally posted</a> by goreefer
"are there automatic dosers for that? "
Yes,
You can set your AC3 up to only turn on the ATO or Doser between any set time, or as I have done is to only allow my ATO to come on when the pH is below 8.2 and shut off when it gets to 8.4. It works really well. I use an ACjr, but both will work the same way.
I top off with Mrs Wages mixed into RODI.

interesting. if i go the ATO route (which i've been contemplating), does the pH swing track evap closely enough to not cause salinity issues? my ato kicks in ~ once an hour for a few seconds, and is pretty sensetive - it detects maybe a 1/4" drop in water level in a 10G sump.

[tmz]

Plus 3. Normal and not a problem .

[goreefer]

<a href=showthread.php?s=&postid=13637169#post13637169 target=_blank>Originally posted</a> by kolosy
interesting. if i go the ATO route (which i've been contemplating), does the pH swing track evap closely enough to not cause salinity issues? my ato kicks in ~ once an hour for a few seconds, and is pretty sensetive - it detects maybe a 1/4" drop in water level in a 10G sump.

My ATO is controlled by a float switch, which is controlled my the ACjr. In the beginning I closely watched the pH swings and adjusted the amount of Mrs Wages that I added to the top off water.
No I do not have any salinity issues, except that it is much more stable that before. The pH is also much more stable than before.
I've actually been very surprised that more reefers do not use this technique.
When you have a very nice tool, such as the Neptune controllers, why not use it for as much as you can.

[IslandCrow]

interesting. if i go the ATO route (which i've been contemplating), does the pH swing track evap closely enough to not cause salinity issues? my ato kicks in ~ once an hour for a few seconds, and is pretty sensetive - it detects maybe a 1/4" drop in water level in a 10G sump.

I don't know if I'd set up the AC to try to control the PH with any sort of drip (like kalk). I think what most people are suggesting is to have it just turn on the ATO at night and keep it off during the day. I've done that, and my only concern was that I'd lose a good amount of water to evaporation over the course of the day. I'd still get my PH spike, but it was at night when PH started off lower. If for any reason you can't use your AC to do this, hooking up your ATO pump to a simple timer will work as well.

[tmz]

Or you could put your kalk on a dosing pump from a still resevoir on a loop separate from your ato and run it on a timer for whatever time period you choose.