pH help

[TrueTricia]

Ok.  So now that I have my Apex set up and its doing its thing, I'm realizing that my pH is low.  I just did a water change a couple days ago, and I've got water going to make another.  

 

That being said:

pH = 7.78 right now, but 7.68 at 10pm last night

Calcium = 440

Alk = 9.1

 

Should I add buffer to raise my pH?  Or is such a low reading at 10pm ok?

[pizzaguy]

Did you calibrate the meter

[pizzaguy]

That is getting a little low Imo . Also put an air stone in your wc water for a day before changing.

[TrueTricia]

Did you calibrate the meter

 

Yep.  It was reading to the 0.01 correct when tested on the pH calibrating solution. 

 

That is getting a little low Imo . Also put an air stone in your wc water for a day before changing.

 

I've never heard of that.  What does that do?

[DuffyGeos]

Open up your window and blow a fan with fresh air over it and see what happens. Mine drops at night since I put a glass top on my 16g IM, but then comes back up in the morning. Mine is 8.04 now, but will be 7.80+/- in the morning.

[DuffyGeos]

Yep.  It was reading to the 0.01 correct when tested on the pH calibrating solution. 

 

 

I've never heard of that.  What does that do?

 

It is all about fresh air. That is why some skimmers have fittings for a fresh air intake. I can't give you the technical reason, but the PH drops in houses since they are so airtight. If you open up your windows the PH goes up.

[TrueTricia]

It is all about fresh air. That is why some skimmers have fittings for a fresh air intake. I can't give you the technical reason, but the PH drops in houses since they are so airtight. If you open up your windows the PH goes up.

Huh. So add fresh air and not buffer? That's so. ... natural.

[AlanM]

PH varies by CO2 in the water. Tap water typically has higher level than atmosphere. So you run an airstone to equalize it. Opening Windows also lowers interior co2 and you can watch pH go up when the windows open. With an Alk of 9.1 it seems like your pH should be a bit higher.

[DuffyGeos]

Huh. So add fresh air and not buffer? That's so. ... natural.

The fresh air will help. Really I don't worry about pH that much. Alk, Ca,then Mag.

[AlanM]

The fresh air will help. Really I don't worry about pH that much. Alk, Ca,then Mag.

Me too, but I can't remember the last time I added magnesium.

[YHSublime]

It was a number you couldn't read before you setup your Apex, and now that it's setup you want to add buffers? Was anything wrong in your tank before that made you want to adjust your PH?

 

As mentioned, your PH will drop at night, and opening a window will probably help. When I run the gas stove my PH spikes, because our place is so small. Look for trends now that you have a starting point. You should have a steady graph that looks like waves, unless that is out of the ordinary, you will probably never check your PH again

 

Now crack a beer and enjoy your tank.

[Djplus1]

It will correspond with your lighting schedule.

[DuffyGeos]

Me too, but I can't remember the last time I added magnesium.

 

 You probably don't have to if you are doing a lot of water changes.  I just know that if my Alk is not staying constant, and my Cal is dropping, that the Mag is low since the Mag helps keep the Cal & Alk in balance. Again, I don't know all the scientific stuff, but I can bring it down to the Reefing for Dummies level of what works.

[Crob5965]

It was a number you couldn't read before you setup your Apex, and now that it's setup you want to add buffers? Was anything wrong in your tank before that made you want to adjust your PH?

 

As mentioned, your PH will drop at night, and opening a window will probably help. When I run the gas stove my PH spikes, because our place is so small. Look for trends now that you have a starting point. You should have a steady graph that looks like waves, unless that is out of the ordinary, you will probably never check your PH again

 

Now crack a beer and enjoy your tank.

 

 

good point, sometimes too much information can be bad, your PH is definitely low, I would try the airstone/ window idea before adding buffers, but like Isaac said if your tank was doing good before you knew about your PH level, you may just end up replacing 1 problem with another by adding buffers.

[howaboutme]

Monitor your ph in the longer run. If you see a nice wave,  your tank is doing good.

 

My ph consistently ran between 7.7 and 8.0 ish. Then I decided it was time to calibrate my probe. Afterwards, it started to read between 7.5 and 7.8. What did I do (it's been a few months)? Nothing. I may re-calibrate it whenever I remember to though. PH is just not a number I worry about.

[TrueTricia]

It was a number you couldn't read before you setup your Apex, and now that it's setup you want to add buffers? Was anything wrong in your tank before that made you want to adjust your PH?

 

As mentioned, your PH will drop at night, and opening a window will probably help. When I run the gas stove my PH spikes, because our place is so small. Look for trends now that you have a starting point. You should have a steady graph that looks like waves, unless that is out of the ordinary, you will probably never check your PH again

 

Now crack a beer and enjoy your tank.

 

LOL.  Good point.  I understand the "don't overreact" mentality.  My concern is that this has been a problem in my tank, even if it's one I couldn't detect.  My corals are doing ok, but could this be affecting them and keeping them from thriving more.

[TrueTricia]

My roommate loves the AC....I much prefer the natural air.  I'm cracking a window now....

[TrueTricia]

Ok.  So I read the Apex wrong.  It's not dropping at night.  It's dropping during the day.  Lowest point is 10 am.  Highest point was 940.

[Orion]

Do not change a thing.  These controllers are nice, but don't start chasing numbers if everything is working fine now.  It'll drive you nuts

[TrueTricia]

Do not change a thing.  These controllers are nice, but don't start chasing numbers if everything is working fine now.  It'll drive you nuts

 

Lol.  I promise I haven't added any buffers.  Just opened windows and added an air stone to my mixing salt water. 

[elbowdeep88]

Is 10am about when your lights come on? And 940 around the timeframe when they go off? Algae consume co2 in the tank via photosynthesis. Co2 is acidic (creating lower ph). Algae only photosynthesize during the day. At night critters are still creating co2 as they resiprate (like we do), but there's nothing actively consuming the co2 since the algae is "asleep". So right before the lights come on (thereabouts) is when you have had hours and hours of CO2 buildup (more acidic, lower ph). Right before lights go out you have had hrs and hrs of algae consuming the co2 so ph should basically be at its highest.

[Orion]

A couple of other suggestions -

 

Was the probe used or brand new? If it was used, was a cap on the end of it when you received it? If not, the probe bulb has probably dried out and is giving you false readings.

 

Make sure the probe is not fully submerged. Unlike the temperature probe, the pH probe cannot be fully submerged.

 

Lastly, these probes are sensitive to EMI (electromagnetic interference) from other equipment around your tank. The wiring is not shielded well, and other equipment when turned on can give you a false reading.

Try turning off various pieces of equipment around your tank and see if the pH changes on the apex. If it does, then you are getting some interference, and you'll have to move the probe somewhere else.

[WheresTheReef]

That ph is a little low, but probably not worth messing with. Buffers are temporary solutions and just another pain to work with. To determine if it is a CO2 problem, take some tank water in a cup and aerate it with an air stone for around 10-15mins near your tank. See what the ph is. Now take the water sample outside and aerate it for the same amount of time and measure the ph. If the ph raises in the outside test sample then fresh air will make a difference. No/little change means that opening a window will likely not make a big difference.

 

My situation was a CO2 problem since my tank is in a basement and my house is sealed up pretty well. My ph was at 7.45ish. When I aerated the water outside, the ph in the cup went up to 8.2 with alk around 9. I ended up drilling a hole on the outside wall, and running some 1/2" pvc pipe to my tank and connected it to the intake of my skimmer. I created a diy inline carbon filter for toxins and dust etc. My ph now runs around 7.95-8.05.

 

To combat low ph due to CO2, another alternative to running a line outside is to run a C02 scrubber. They tie into your skimmer and uses C02 absorbing media (lime pellets). BRS sells that stuff. I went with airline since it was a short run and I didn't want to mess with changing out the media once it was exhausted.

 

Might also want to test the ph of the new saltwater. My ph drops a little after a water change since the ph in the new water is a little lower than the tank.

Edited August 20, 2014 by WheresTheReef

[zygote2k]

throw the pH meter away and go about your business. I stopped worrying about pH and I haven't had any more problems.

[Origami]

New pH probes can take a little while to settle in. Don't chase numbers and, if your tank is looking good, take double the time to consider if changes are warranted. Calibrate your probe again after a few days. And, if your pH is at 7.7 or higher - maybe even 7.6, I wouldn't worry a lot.

 

As Alan said, the variation in pH is driven mostly by the balance of CO2 in your water. This, in turn, is driven by the balance between photosynthesis and respiration, which ties it to your light cycle. CO2 in water forms carbonic acid, driving pH down. During the day, algae and other photosynthetic organisms (which includes a lot of corals), consume CO2 and water, and use light to create sugars which are used as fuel. This has the effect of reducing CO2 which raises pH. At night, all of the cells (including algae) sustain their processes through respiration. This process consumes sugars and oxygen to produce water and CO2 and energy to drive the cell. This release of CO2 drives pH down.  The result is what we call a diurnal variation of pH. 

 

Tricia, do you have a sump with macroalgae on your tank? If so, you can try lighting it on a reverse light cycle. That is, with the light on at night (opposite the tank's light cycle). This can help even out the diurnal variation.