randy another ph question

[imbuggin]

Randy I have a question for you. On my 300 gallon sps reef of 7 years I added a calcium reactor to go with my dosing pump with b-ionic. My ph used to be 8.0 - 8.2 night to day. Now it is 7.8-8. Recently I noticed it drop to 7.7 at night and go to 7.9 during the day. If I use buffer it gets to 8.1 but only for a day or so than back down. The corals seem happy and show great color and growth. Is 7.7 dangerously low?

My water specifics are
alk 11-12
Calcium 400-410
Ph 7.7 -7.9
0 phosphates
0 nitrates, amonia, or nitrites
ph from 2nd reactor chamber 6.83

What could I do to keep the ph up at night. Would adding and air stone in the sump to add more oxygen help? I already have a large skimmer. How about ozone? Would it effect the PH or just ORP? Thanks for any input

[Randy Holmes-Farley]

A pH of 7.7, if accurate, is fairly stressful for corals, and I'd try to raise it. Many folks in a situation like yours use some limewater to boost the pH. The buffer is not a good way as it will push the alkalinity too high, and not help pH enough.

How are you measuring pH?

[imbuggin]

i have a ph controller on the reactor and and electronic milwaukee monitor on the tank. I should check the calibrations as well.

Could I drip calk or will that shoot the calcium up too much as well? I have never used limewater in the past. Can you give me the basics or a link to where i could find it?

[Randy Holmes-Farley]

Dripping limewater (kalkwasser) is what I meant. Here's a link to a cheap way to do it:

http://reefkeeping.com/issues/2004-06/nftt/index.htm

Yes, I'd check the calibration of the pH meter.

This article may also help:

Solutions to pH Problems
http://www.advancedaquarist.com/issues/june2002/chem.htm

[imbuggin]

thanks

[Randy Holmes-Farley]

You're welcome.

Let us know what you find. :)

[imbuggin]

Randy Here is an update. I thought i solved the problem, but its back. After reading all the articles and following you suggestion I began to drip kalk to raise the PH. I stopped the b-ionic dosing. Slowly turned it down as the kalk dosing went up. For a while it was working ok keeping the ph 7.8-8 and above the 7.7 that scares me. Today overnight it dropped back to 7.7? I am adding as much kalk water as I can? I also turned down the flow rate of the reactor. I buffered the tank to boost it back up to 8.0, but know that isn't the best solution and will not last for long.

alk 11
ca 420
na,no,ammonia 0
81 degrees
2-chanber reactor effluent 6.75

The only thing I have not tried yet is getting the skimmer to pull fresh air from outside. Do you have any other suggestions? I don't want to have to start with the b-ionic again. I was dosing soo much it was costing a small fortune and is a P.I.A

Thank randy

[Randy Holmes-Farley]

How much limewater are you adding? How much lime in it?

[imbuggin]

I am dosing about 2 gallons of fully saturated lime water (lots of resedue on bottom of container). That is about the amount of evaporation I am getting a day. Do i try to evaporate more via a fan on the sump or something? The tank is already open top with 4 400 watt bulbs?

[Randy Holmes-Farley]

Yes, increasing evaporation is one option.

Have you tried aerating a cup of water outside and seeing if the pH rises?

[imbuggin]

Originally posted by Randy Holmes-Farley
Yes, increasing evaporation is one option.

Have you tried aerating a cup of water outside and seeing if the pH rises?

Nope, but good idea. I will try it tonight. How long should it take to notice a difference?

[Randy Holmes-Farley]

An hour aerating a cup of water with an airstone shuold suffice.

[imbuggin]

Ok i may have "solved" some of the problem and wanted your thought. When my ph started to drop it also was at the same time I added a waste collector on my skimmer. The ones that will turn off the venturie action in the skimmer if the waste level gets too high. So the skimmer was pulling air out of the chamber that collects the skim scum on the bottom of the container. Do you think the scum could make the air in that chamber higher in co2 than regular air? So that i was using not as fresh air as before? Since i pulled the air intake off the chamber the ph has held 7.8-8. Still a bit low but exceptable. I am also still dosing kalk btw.

[Randy Holmes-Farley]

That's possible, I guess. Perhaps some of the skimmate was decomposing, releasing CO2.

[imbuggin]

Originally posted by Randy Holmes-Farley
That's possible, I guess. Perhaps some of the skimmate was decomposing, releasing CO2.

thanks that is kinda what I thought. The only other thought was that something in the skimmate was photosynthetic and give off co2. I highly dought that though. 1 no light in that cabinet and 2 as far as I know skimmate has little plant life alive in it?

[Randy Holmes-Farley]

Photosynthetic organisms take up CO2, so that wouldn't be it. :)

[imbuggin]

duh..i knew that. sorry:rolleye1: