Jestersix

What would make my PH drop really low out of nowhere?

badbread

badbread

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Woke up to a tank around 7.70 PH this morning. Got an email warning on my Blackberry from the Reefkeeper software saying PH dropped below 7.8

I didn't do anything to the tank last night really, moved 1 coral around, dosed a tiny bit of KH 2-part. Kalk was still dosing as usual. Does this just happen sometimes?

Picture is of this weeks PH readings:
phdrop.jpg
 
Negative. My new neighbors across the hall are super pot heads and from the smell of it they had a valentines weekend Hempfest last night, think that would do it?
 
I get low readings like that sometimes and it always turns out to be one of these

1 something gunked the probe (scrubbing w/toothbrush takes care of it / usually use the wifes toothbrush)

2 kalk reactor is in need of more pickling lime

3 my litermeter III needs to be cleaned (something binding at the pulsating parts/ causing a smaller amount of lime water to be dipensed or none at all)

good luck
 
Not really, did some very light target feeding (Yuma's and Blasto's) and moved a slimer around, that's it. Slimer didn't slime up from being moved as it was a quick painless move.
 
[quote author=saltwatersig link=topic=6345.msg81008#msg81008 date=1234550581]
I get low readings like that sometimes and it always turns out to be one of these

1 something gunked the probe (scrubbing w/toothbrush takes care of it / usually use the wifes toothbrush)



good luck
[/quote]

LOL...spoken like a true husband
 
Well, for whatever reason the PH tanked again last night. It's been fine until last night and then boom, went way low into the 7.5's...

Image shows right before lights out, at 5:55PM PH is at 8.31



Throughout the night PH dropped by about .01 - .03 every 15 minutes. Nothing was done to the tank, kalk was dripping as usual every hour for 3 minutes via an aqualifter.

7:20AM PH bottoms out at about 7.52
7:30AM I turn on the lights 1/2 hour early and it starts going up again.

Day:
phtank1.jpg

Week
phdrop2.jpg

Month:
phdrop3.jpg

Looking through my logs it seems like this happens every 7-10 days, what could be going on?!
 
An addendum, these drops do not co-incide with any water changes or anything like that, usually post water change not much changes on the PH side of things.

Tested my parameters last night and all tested well:
Alk Calc Mag PH Salinity
17 Feb 2009 9.00 440 1340 8.13 1.0260
 
Did you have the house completely closed up and people visiting?

PH can drop if all windows and doors are closed and when you have people in the house. I never really thought about it until I had a bunch of people over last Sunday for dinner. Just after they left I checked my controller and PH showed 7.97 and normally it's always 8.15 - 8.20 around that time.
I opened the kitchen door and after 45min ph had gone up to 8.02 when all lights were off except the fuge lights.
 
[quote author=alve link=topic=6345.msg82444#msg82444 date=1235000424]
Did you have the house completely closed up and people visiting?
[/quote]

pH drops at night due to respiration, coral and human. Effects show more with more people and less ventilation. Particularly during cold weather season.

It can help to run your skimmer air intake to a source of fresh air.
 
Do you have a Calcium reactor? Not sure why it would drop sharply at 3am. it should be a slow dip during the entire night. If you have a fuge you can also do a reverse light on it to help keep PH steady....
 
As I last recall 2/13 was pretty yucky weather as was 2/12. Is it possible that the house is locked up tight - maybe the heat was on?
 
I dunno but my planted tanks do the same thing at night right after lights out.. The ph will drop until it hits around 6.0 or so . When the lights come back on it will come back up to 6.8 or 7..
 
[quote author=fishnfst link=topic=6345.msg82489#msg82489 date=1235010084]
I dunno but my planted tanks do the same thing at night right after lights out.. The ph will drop until it hits around 6.0 or so . When the lights come back on it will come back up to 6.8 or 7..
[/quote]

Yep, that's standard biochemistry with the switch from photosynthesis to respiration. Respiration generates CO2 which drops your pH.

So if your pH dips in your reef tank are due to CO2, you can double check that you have enough water circulation so that you don't compound the problem with inadequate gas exchange.
 
phtank1.jpg


The S curve behavior over the course of the day looks like normal healthy system response to me.

If your average pH is low, I would look for improving ventilation and gas exchange.
 
I was dealing with low PH in this tank for a while. After re-calibrating my PH probe with 7 & 10 solution instead of 4 & 7 solution I discovered that this tanks PH was always on the low side. To help remedy that I did a lot of things:

• Ok, so there is no calc reactor in the system.
• I set the back chambers intentionally low so that there is a slight waterfall so I get more gas exchange
• I moved the Vortech closer to the top of the aquarium so there is a nice ripple, and moved a few of the spray bar nozzles upwards for a nice ripple as well (gas exchange)
• I modded the filter basket to hold a couple big balls of chaeto and and installed a hang on light on a reverse light cycle back there
• I moved the skimmer air pumps out from underneath the cabinet to outside of the tank
• I started dosing kalk

After all that I got my PH where it needed to be, but that is all in the past!!

My landlord recently replaced the back door in my apartment, I went from a shitty old metal frame, single pane sliding glass door to a fancy new double pane sliding glass door. I'm sure that is insulating my place A LOT better than before. I know this could be a cause but this same thing happened last week when I still had the shitty old metal sliding glass door. It has been some crappy weather and the heat has been on but it's electric heat/electric stove, that doesn't produce any CO2 does it?

Tonight I opened the back door for a few hours and ran one of the skimmer air pumps all the way back to near the sliding glass doors. The PH isn't tanking like it did last night but it's still pretty low. Everything in the tank is fine, and I'm not worried about the 'ish really hitting the fan on this one.

Really I'm just wondering why on some nights the PH goes so low. I understand the whole photosynthetic process and how it relates to PH and that some swing is normal but was really curious as to why just some nights the PH dips so so low.

Is it something to do with the tides, areas of low/high pressure and coral response, moon phase, Professor Plum in the Observatory with the candle holder, spare the air days, pot head neighbors, etc...

Thanks for your time!
Jay
 
Looks like very nice respiration curve, as Norm mentioned. Essentially all your photosynthetic organisms are sucking the CO2 out of the water at the end of the dark phase of photosynthesis. It is very natural, but unfortunately your tank does not have the vastness of the ocean to buffer this pH drop.

Lighting your chaeto at night is probably the most important step you took. If you can simply add a bubbler to the tank I would think that would also help. The kalk drip is always a good idea to keep to help build your buffering potential. I would think that atmospheric conditions would have little influence on your tank, but it might be a function of nutrient availability (or limitation) in your tank, like say N, which if there was a additional N in the tank, your chaeto would love it and you would see an increase in photosynthetic respiration. In a closed system it might just be a snail dying, overfeeding, etc that would stimulate your more your algae.

Do you have a way to record your N real time? That would be really cool to map out N vs pH vs CO2 concentrations, you could probably publish it in a aquaria journal.

Cheers,

Josh
 
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