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View Full Version : Stubborn PH - About to give up and get out


Reefers4U
06/16/2014, 02:42 PM
Ok folks. I have been battling low PH since around November.

I can't understanding it at all. I'm pretty sure that this is a CO2 issue for several reasons:

1) The PH rises when I use the cup outside with an air stone method.
2) If I have a window open all the time I am able to get the ph to 7.9 - but it must be open 24/7 - I live in south Florida.
3) When I recently went on a trip both my animals and I were out of the house. The PH seem to raise to 8.0 and it stayed that way until I came home. I know this because I have a controller.

I'm at the end point for me. My tank is totally empty I keep running it day after day opening and closing windows. Trying to run soda lime to strip out the CO2 but it doesn't take long to clog up.

Does anyone have any suggestions here - I'm about to quit the hobby. Just when I dialed in my tank with LEDS, dosing pumps and new returns I now can't get my PH up and I've just about had it with the tank and the hobby.

I'm not new to this hobby. I've been keeping reef tanks for 10 years now. This is the only tank I've ever had a PH issue with.

Can anyone help?

Is there a chance that my sand could be giving off CO2 or my Air Conditioner?


p.s. other than that my params are perfect. I test with Hagen and Hana testers.

disc1
06/16/2014, 02:51 PM
How are the animals? If they're looking OK then I would forget about the pH battle. 7.9 is perfectly fine.

TigeBell
06/16/2014, 03:10 PM
I hate to ask but do you smoke in your house around the tank?

Reefers4U
06/16/2014, 03:28 PM
only thing in there right now are two shrimps and an anemone thats hanging on for dear life. snails and hermits look fine.

Randy Holmes-Farley
06/16/2014, 03:33 PM
Is there a chance that my sand could be giving off CO2 or my Air Conditioner?

Nope.

How low does it get under normal circumstances?

How are you maintaining alkalinity?

downbeach
06/16/2014, 03:37 PM
When was the last time you calibrated your pH probe? How long have you had it?

SloppyJ
06/16/2014, 03:41 PM
Why are you chasing your pH?

Randy Holmes-Farley
06/16/2014, 04:20 PM
FWIW, the fact that the pH rises with outside aeration suggests it is not just a calibration issue, assuming it rises into the normal range of 8+. :)

Breadman03
06/16/2014, 04:48 PM
Your post implies that you run a skimmer. Have you considered running the intake hose outdoors? That should make a notable difference.

hilgert
06/16/2014, 04:50 PM
If you don't open windows, and you and your dogs are home, what is the pH at?

While it does sound like you have a CO2 issue, you still need to make sure your pH measurement is accurate. How long has it been since you've calibrated your pH probe? If it's been more than a few months then I suggest you calibrate your probe with new-in-package pH calibration fluids...7.0 and 10.0 (which covers the range we are interested in). That will confirm if your pH is actually what you believe it is. I calibrate mine every few months...you might be surprised at the drift.

To raise pH you could consider using kalkwasser. Before I started dosing kalkwasser several years ago I had 7.9-8.0 pH for years (without issues...good tanks), but with kalkwasser I'm now in the 8.20-8.35 range. Getting higher pH was not the only reason I switched...it was just one of the benefits that caused me to switch back (I'd used kalk before MANY years back before going to 2-part).

jgalen0025
06/16/2014, 08:39 PM
you said your current inhabitants are not doing well, but IMO it has NOTHING to do with pH and it could be do to a number of other things.
When I moved my tank to my basement, during the spring and the fall with no home heat or air cond on to circulate air my pH went from 8.1-8.3 to 7.7-7.9 and everything is still doing just fine. Stop chasing pH.

hilgert
06/16/2014, 08:52 PM
Some good reading on pH:
http://reefkeeping.com/issues/2007-05/rhf/

kaskiles
06/17/2014, 05:26 AM
It's pricey, but you could tie in a home air exchanger to your pH monitor. I assume you're already trying some photosynthesis with a reverse daylight fuge...

Randy Holmes-Farley
06/17/2014, 05:34 AM
IMO, if the pH drops below 7.7, and that pH is real, it is worth the effort to bring up the bottom end. Coral skeletons can begin to slowly dissolve at that pH or lower.

bertoni
06/17/2014, 03:55 PM
Have you posted an alkalinity measurement?

Only a gas-powered appliance could lower the pH by producing carbon dioxide, basically speaking.

Reefers4U
06/18/2014, 07:45 PM
Sorry for the late response. I had to rewrite my responses because it erased my responses when it asked me to log in.

First I need to thank everyone for their help and time. It is very much appreciated.

I dont' smoke cigarettes at all.

@RHF: it gets to 7.66-7.69 normally without the windows open. I am maintaining alk by dosing BRS two part.

@downbeach: Jan/Feb when I was having the same issue. I wanted to make sure it wasn't the probe. When I add buffer it goes to 8.1 but slowly drops down over a period of 8 hours. I will get more packets and try again but I'm reasonably positive this isn't the problem.

@Breadman: I do run a skimmer - I tried this with my old skimmer without much luck. After getting a new skimmer I will try this again to see if the results differ. I have placed a DIY CO2 scrubber on the end of the intake using soda lime but this gets saturated within a few days - turns purple. I also have taken poly filter and put soda lime in the middle and placed it in the intake of my AC - it too gets saturated within several days.

@JGALEN/SloppyJ: Sorry guys I lost 900 in coral frags - they were doing well for a few months and then the pH took a dive and lost them all. I need to solve this pH problem. I also think its a main reason why coralline algae won't grow.

@Kaskiles: I've never heard of this before. I will look into it. Correct on the fuge, Have cheato in the sump off cycle.

So the only thing I can think of doing is getting an exhaust fan and placing it by a window and changing out the air in the house every day - or moving. This place is made of block (old) and I have a feeling its very well insulated.

I will remeasure alk and post in a few hours

Reefers4U
06/18/2014, 09:58 PM
alk registers at 254 PPM using hanna checker

Reefers4U
06/18/2014, 10:08 PM
you said your current inhabitants are not doing well, but IMO it has NOTHING to do with pH and it could be do to a number of other things.
When I moved my tank to my basement, during the spring and the fall with no home heat or air cond on to circulate air my pH went from 8.1-8.3 to 7.7-7.9 and everything is still doing just fine. Stop chasing pH.

Could you expound on the "number of other things" - you might be right but I don't know what they could be :D

Justdrew
06/18/2014, 10:16 PM
alk registers at 254 PPM using hanna checker

That is pretty high on the alk reading. 14.2 dKh.

tmz
06/18/2014, 10:18 PM
Alk at 14 dkh(254 ppm) could be causing the trouble the corals are having more than the low pH. It probably got that high using buffers to raise pH which almost always results in the same low pH and higher alkalinity as CO2 from the air equilibrates with tank water in a matter of hours .

What is the salinity btw.?
Calcium?

How long does it take for the soda lime to change color ,btw?


7.69 is low enough to warrant some attention ,IMO, as calcium carbonate including coral skeletons can begin to dissolve at levels under 7.7

An outside air line to the skimmer might help raise the pH in view of teh aeration test.

I'd stop dosing alkainity and make sure the calcium was at at least 380ppm . Once you get the alk down into an acceptable range, 7 to 11 dkh, switching to calcium hydroxide dosed slowly 24/7 in lieu of two part to maintain alkalinity and calcium levels will help as it uses CO2 to form CO3(carbonate) thus reducing the CO2 level in the water continuously.

dartier
06/19/2014, 12:39 AM
I also have a tank in a basement and have had a PH that will drift lower than desirable. I have also had my struggles keeping SPS so I feel your pain.

Here is what I have found that can help (all already mentioned by others).


Dose Kalkwasser. This helped the most for keeping the PH up.
Run an external air Line for the skimmer
Install a HRV system and keep it in a constant exchange mode
Run a reverse photo period fuge


My PH now stays between 8.0 and 8.15 using 2,3,4 from my list. The most important thing that I have found (and why I no longer utilize #1) is keeping my Alk stable. Alk swings lead to STN for SPS and corals in general. As others have pointed out, it is most likely the Alk swings that is your undoing.

Unfortunately my husbandry is just not up to being able to keep up with the speed that Kalk loses its potency in my tank's location. If you are up to the task though, it is very effective at raising PH (and providing Alk and Calcium). Just make sure you dose it in a slow and steady way that keeps your Alk stable.

Keeping my Alk stable long term has allowed my SPS frags to live long enough for me to realize that I have Montipora Eating Nudibranches in the tank. Yea, more fun .... :headwally:

Dennis

Reefers4U
06/19/2014, 08:32 AM
@tmz: you are spot on re: the buffer. It keeps kicking my alk higher and higher.

@dartier: thanks for the tips - I will try them all - right now the HRV is beyond my purchasing capacity. If it comes down to that I will move or shut the tank down. Sorry to hear about the Nudi's man - this hobby is like dating a gorgeous woman who is also crazy, you love her, but its always something....

calc is 400 using salifert
sal is 1.027 using ATO Refractometer

So after a water change I should stop using the two part and just dose kalk with my peristaltic dosing pumps?

I will run the skimmer line tonight and see what the results are.

I am leaving for a conference on Saturday and returning Weds. I'm willing to bet the pH returns to normal.

But the question remains, that if I leave (with my pooch), the pH rises to around 8.0 - according to prevailing theory on this thread, the high alk levels should still prevent that from happening right?

I'm not clear at all on the interaction between pH/Alk/CO2.

Are there any calculators out there that can help me determine how much water I need to change to bring down the alk? 90 gal (accounting for the sump and displacement of rocks and sand) - 30%?

Reefers4U
06/19/2014, 08:38 AM
sorry - RC is doing something strange, it keeps asking me to log in. then when I go to edit the thread it says I don't have permission and to log in. :angryfire:

it takes about 12-48 hours for the lime to change color and saturate.

tmz
06/19/2014, 09:04 AM
sorry - RC is doing something strange, it keeps asking me to log in. then when I go to edit the thread it says I don't have permission and to log in.

That happened to me last week. Next time you log in be sure to click "remember me";that worked.

tmz
06/19/2014, 10:03 AM
@tmz: you are spot on re: the buffer. It keeps kicking my alk higher and higher.



calc is 400 using salifert
sal is 1.027 using ATO Refractometer


Those are ok.

So after a water change I should stop using the two part and just dose kalk with my peristaltic dosing pumps?

No, stop dosing alk,the kalk will add alk, and let it fall into an acceptable range. Water changes will have minimal effect since newly mixed salt water also includes alkalinity. Keep the calcium at 400ppm or a tad higher.

I will run the skimmer line tonight and see what the results are.

If you use an outside air tube for the skimmer make sure it is large enough to avoid restricting air flow ;usually stepping down a larger diameter tube or piece of pvc near the skimmer air intake will accomplish this.

I am leaving for a conference on Saturday and returning Weds. I'm willing to bet the pH returns to normal.

But the question remains, that if I leave (with my pooch), the pH rises to around 8.0 - according to prevailing theory on this thread, the high alk levels should still prevent that from happening right?

The alkalinity will buffer CO2 changes in the tank water but doesn't account for the variable rate of CO2 equilibrating from the air and the H it adds as it hydrolizes .

I'm not clear at all on the interaction between pH/Alk/CO2.

It's a little complicated and most who are not trained chemists including me have had trouble getting their head around it.
I'll try to give a short version ,as I understand it , but recommend Randy's articles on it for a better understanding in depth.

Alkalinity is not a thing ;it is a measure of the ability of the water to neutralize acid; it includes many things( carbonate, bicarbonate, phosphate,etc).
Approximately 96.5% of the elements contributing to alkaliniy in salt water is carbonate alkalinity. Carbonate alkalinity is what corals and calcareous organisms use but hobby grade tests test total alkalinity which is used as a surrogate measure for carbonate alkalinity( carbonate/CO3, and bicarbonate/CHO3).
The proportion of CO3: CHO3 varies depending on the amount of H+ (measured as pH), which shifts the equilibrium : CO3<----->CHO3<----->
CH2O3( carbonic acid,most of which is disassociated in salt water) .CO3 can neutralize 2 H protons ;CHO3 only has room for one;carbonic acid none as it's an acid.

PH is a measure of H ,more H+ equals more acidity which equals more H2CO3 ,less CO3 and more carbonic acid .

CO2 adds H protons when hydrolized. CO2 +H2O = CH03 plus H. So ,it adds two H protons taken from the water lowering the pH. It has no effect on the total carbonate alkalinity since it utimately replaces one carbonate ion worth two units of alkalinity(acid neutralizing capacity) with 2 CHO3 ions each worth one unit of alkalinity.

Hope that helps








?

Randy Holmes-Farley
06/19/2014, 10:05 AM
I'm not clear at all on the interaction between pH/Alk/CO2.

It is a purely mathematical relationship in seawater, discussed here:

http://www.advancedaquarist.com/2002/5/chemistry

an less mathematically here:

The "How To" Guide to Reef Aquarium Chemistry for Beginners, Part 3: pH
http://reefkeeping.com/issues/2007-05/rhf/index.php

from it:

Figure 2. The relationship between alkalinity and pH in seawater with normal carbon dioxide levels (black), excess carbon dioxide (purple) and deficient carbon dioxide (blue). The green area represents normal seawater.


http://reefkeeping.com/issues/2007-05/rhf/images/image002.jpg

tmz
06/19/2014, 10:32 AM
it takes about 12-48 hours for the lime to change color and saturate.

That's very fast;most get from 2 to 5 weeks out ofthe soda lime . There must be a high of CO2 in the air. Perhaps the reactor you are passing the air through is letting too much air in and out ;basically attempting to strip CO2 from the whole room.

Reefers4U
06/19/2014, 10:55 AM
@TMZ I know, crazy fast. I am trying to figure out a way to measure the C02 in the house. But the testers are very expensive or they only measure Carbon Monoxide. When you say reactor, I'm assuming you mean the CO2 scrubber - which is a pee cup, with holes drilled in the lid to let air pass through, the skimmer's air intake line is fed into the bottom of the cup. I'll post some pics. But I'm always sure to fill it up with enough media so that there are no spots where air doesn't have to contact the lime to get to the air tube.

I'm a bit confused with the graphs. It says that I should have a pH of 8.1 with a meq/l of 5 (which is 14 dkh or 254ppm)?

And are we suggesting that the alk is causing the low pH and high CO2 levels?

I could just add RO/DI water, reducing the alk and sal levels. I haven't dosed Alk in many months.

I apologize I know that compared to you guys I'm a moron at understanding this stuff. I will try to find time to consume those articles to make myself better educated so that I'm not asking dumb questions and wasting ppls time

Randy Holmes-Farley
06/19/2014, 11:16 AM
I'm a bit confused with the graphs. It says that I should have a pH of 8.1 with a meq/l of 5 (which is 14 dkh or 254ppm)?

There are three lines, but only one is set in stone: the normal CO2 graph line which is what you'd have if your tank was perfectly equilibrated with normal outside air.

The other two are simply examples. The lines can shift closer to the normal line or farther from it, depending on whether the amount of CO2 used in the example is more or less extreme. :)

That said, a great many tanks are not far from the purple line, at least by the alk and pH numbers they report here. :)

TigeBell
06/19/2014, 11:37 AM
Your salinity is of 1.027 would be considered too high by a few people here. Try to get that down to 1.026 or a little lower.

Reefers4U
06/19/2014, 01:00 PM
Your salinity is of 1.027 would be considered too high by a few people here. Try to get that down to 1.026 or a little lower.

Yeah. For me too. Thats why I'm thinking of doing a water change with buffered RO/DI to reduce both the alk and sal.

disc1
06/19/2014, 01:06 PM
Yeah. For me too. Thats why I'm thinking of doing a water change with buffered RO/DI to reduce both the alk and sal.

If you put buffer in it, then it won't reduce the alkalinity. If you want to lower salinity just take out some saltwater and replace with freshwater. There's no need to buffer anything.

TigeBell
06/19/2014, 01:33 PM
Yeah. For me too. Thats why I'm thinking of doing a water change with buffered RO/DI to reduce both the alk and sal.

If you put buffer in it, then it won't reduce the alkalinity. If you want to lower salinity just take out some saltwater and replace with freshwater. There's no need to buffer anything.

I would do what disc1 suggests. Slowly lowering the alk and sal would be best. Too fast and you could have things go wrong. :(

pscott99
06/19/2014, 01:37 PM
Long shot but in the interests of your health and safety.

Have an HVAC or weatherization contractor measure CO2 levels within your home.

DENIZSEAMAR
06/19/2014, 02:11 PM
I have pH problem but on the other side. It is between 8.4-8.6. My kH is between 6-7 . And dosing Kalkwasser. But cant dose kalk more to reach 8 kh coz pH gone crazy to 8.7.

Randy Holmes-Farley
06/19/2014, 03:01 PM
IMO, the salinity is not too high, but lowering it a bit also certainly won't hurt anything. Much of the reef-covered parts of the ocean have salinty at that level of higher. sg = 1.027 is 35.8 ppt. IMO, 34-36 ppt is a fine range to target see map below

Lowering salinity won't alter the pH, so don't do it for that reason. :)


Map of ocean salinity
from: http://www.salinityremotesensing.ifremer.fr/sea-surface-salinity/salinity-distribution-at-the-ocean-surface

http://www.salinityremotesensing.ifremer.fr/_/rsrc/1286917514134/sea-surface-salinity/salinity-distribution-at-the-ocean-surface/annual_clim.jpg?height=1641&width=3015

tmz
06/19/2014, 03:25 PM
I often run my tanks at 1.027 ;the seawater average is 1.0264. Posted this before I read Randy's post 34 to 36ppt,ie 1.026 to 1.027 sg is fine ,imo.

However, if you want to drop it from 1.027 to 1.026 ;just remove 3.7% of the tank water and replace it with pure ro/di water ;no buffers. That drop will result in a drop in all the solids including alk and calcium by about 3.7%.

Reefers4U
06/26/2014, 12:19 PM
Ok guys. Back from my trip last night and the pH was at 7.85 when I came home. Continued to watch it and it stayed steady there.

Suggestions I have yet to implement but will in the next 72 hours.
1) run skimmer air line external
2) calibrate probes

I was going to reduce the sal further from current level of 1.025 but think I'm happy there.

Current alk levels are 11.4 dkh.

Right now, off cycle the pH is stable at 7.77/8

bertoni
06/26/2014, 02:52 PM
Alkalinity at 7.8 is fine, IMO. Many Tanks of the Month run at that level. The suggestions about fresher air are correct, but I wouldn't worry about the tank at this point. If there are problems, the cause probably is elsewhere.

Reefers4U
07/05/2014, 11:54 AM
update:

I installed an extension to the skimmer's air intake and ran the other end outside.

This has seems to have solved the problem. 12 hours after the line was installed the pH rose to safe levels of 7.8. It rose to 8.02 yesterday and if the trend keeps, should be at 8.2 by tomorrow.

It seems the combination of high alk, a crappy skimmer (I tossed out my wet/dry and retrofitted the sump with a new skimmer) and high CO2 levels were acting in concert to keep my pH low.

Sadly, I lost all my beautiful corals in the 8 months it took me to figure it all out. I thank many of you who took the time to get me straight for this small victory. Now time to start rebuilding.

While thinking about my tank, I wondered if the amount of corals or fish has in the system can cause depressed pH through respiration? Since I know CO2 to be high in this house, do I have to be more careful with stock limits on my system?

Thanks again everyone. Your help is greatly appreciated.

JG

Randy Holmes-Farley
07/05/2014, 12:17 PM
Good aeration will help drive the CO2 levels toward equilibrium with your home air, but insufficient aeration can cause excess CO2 at night, and hence low pH, even with normal stocking levels.

Just to be clear, high alkalinity didn't contribute to the low pH. :)

tmz
07/05/2014, 12:49 PM
Unstable alkalinity might stress organisms.

When potosynthesis stops or slows down, less CO2 is used. Some run macro algae refugia on opposite phoperiods to help this . I stagger photoperiods a bit on a multi tank system.
A good skimmer with fresh air will have a positve effect day and night as you are seeing.

Sufficient aeration primarlily from the skimmer (in your case since house air is high in CO2) with CO2 at athmospheric levels (fresh air) or less will rasie the pH probably more so if you cover some open water in the system or circualte fresh air to the room.

DavidinGA
07/05/2014, 01:14 PM
#1 Run your skimmer airline outside.

#2 dose Kalk (will help tremendously!)

However, a pH of 7.9 is fine imo.

Reefers4U
07/05/2014, 01:58 PM
good to know RHF thanks. I assumed high alk had a contributory factor because I had previously tried extending the airline outside without decent results. The only new changes to the experiment were the alk and new skimmer.

So then is it reasonable to conclude the old skimmer's intake from fresh air was too small to offset the tanks CO2 from the home air/off photo periods?

Sorry, I'm trying to make sure I've solved the problem before irresponsibly buying more coral

dkeller_nc
07/05/2014, 02:04 PM
While thinking about my tank, I wondered if the amount of corals or fish has in the system can cause depressed pH through respiration? Since I know CO2 to be high in this house, do I have to be more careful with stock limits on my system?


I just read this thread for the first time. My major comment would be that presuming that your pH calibrations are accurate, your probe is in good working order, your tank's gas exchange is reasonably good and your alkalinity measurements are reasonably accurate, you've a problem, but your reef tank's the least of it.

In order to get a pH as low as some of your posts noted with the alkalinity that you measured, you'd have to have a really high level of CO2 in the atmosphere of your house. You're still likely to be under the OSHA limit of 5000 ppm (0.5%), but I'd be concerned that you have an uncontrolled source of CO2 emission into the house (other than you and your dog).

One test that'd be worth doing and is inexpensive, is to get a measurement of freshly mixed Instant Ocean in a 5 gallon bucket that's been aerated with a small air pump and air stone for an hour. You should get pH 8.2 at least - if you get less than 7.8, I'd seriously consider getting an HVAC contractor to measure the concentration in your home.

Randy Holmes-Farley
07/06/2014, 05:13 AM
good to know RHF thanks. I assumed high alk had a contributory factor because I had previously tried extending the airline outside without decent results. The only new changes to the experiment were the alk and new skimmer.

So then is it reasonable to conclude the old skimmer's intake from fresh air was too small to offset the tanks CO2 from the home air/off photo periods?


That's certainly possible. . How you add alkalinity impacts pH, but once it equilibrates with the air, the higher the alk, the higher the pH. :)

Reefers4U
07/06/2014, 07:27 AM
well the increase stalled for some reason. Any thoughts on why the peak of the pH didn't get as high as it did the night before?

The highest peak on the graph is 8.02. You can see I added the airline to the skimmer around noon on July 2nd.

The tank is operating at safe levels but I'm just nervous the pH is going to slide back down again.

@ dc keller: I'd be interested in getting this checked out. In 10 plus years in this hobby I've never had such a hard time getting a tank in order. I've been in this place since 2012 without any pH issues, this just cropped up in November so I'm not sure what's happened or what could have changed in november to cause this.

Do I just google local HVAC, anyone should have the kit or should I be looking for someone more specific?

inetmug
07/06/2014, 08:42 AM
I just read this thread for the first time. My major comment would be that presuming that your pH calibrations are accurate, your probe is in good working order, your tank's gas exchange is reasonably good and your alkalinity measurements are reasonably accurate, you've a problem, but your reef tank's the least of it.

In order to get a pH as low as some of your posts noted with the alkalinity that you measured, you'd have to have a really high level of CO2 in the atmosphere of your house. You're still likely to be under the OSHA limit of 5000 ppm (0.5%), but I'd be concerned that you have an uncontrolled source of CO2 emission into the house (other than you and your dog).

One test that'd be worth doing and is inexpensive, is to get a measurement of freshly mixed Instant Ocean in a 5 gallon bucket that's been aerated with a small air pump and air stone for an hour. You should get pH 8.2 at least - if you get less than 7.8, I'd seriously consider getting an HVAC contractor to measure the concentration in your home.

I am surprised it took so long for someone to post this. I just read this today AM, and this is the first thing I would have said as the rest of the crew has a handle on the details.

How is your home sealed? And how is your AC working, do you have it on a humidistat, especially in S. FL? You should be getting about 6-8 air changes in your home per hour. When I was building homes, I had several zero energy cost home designs pendiing before the bust. The homes "envelope" was so tight, that we had to add outside air induction into the AC system to meet codes. Sometimes all new windows, doors, isothane insulation, etc., can cause other issues. I developed these designs with the Florida Solar Energy Center.

The radon testing guys should be able to give you more help. Most times in the construction industry we are concerned with CO, not CO2. Not sure how CO2 would affect health, but radon sure does/can. I know from diving excessive C02 by skip breathing can lead to headaches, basically lower oxygen levels in the blood.

Look here:

http://www.propex.com/C_f_env_co2.htm

It talks about the exact thing I was mentioning, mechanical exchange with outside air. I have never seen a CO2 detector, but apparently they exist.

One other thing, do you have a kegarator in your house that could be leaking C02? You could also put up a houseful of plants.

Randy Holmes-Farley
07/06/2014, 08:53 AM
I'm not sure why it didn't peak again (could be many things, such as more home CO2 that day or less photosynthesis, for example) but I wouldn't try to overanalyze it. If it drops too low again, that's when to worry again. :)

Reefers4U
07/06/2014, 09:56 AM
I'm at work and its slow - so this thread benefits from my excess time :)

@RHF - As usual, you are right - thanks for the sound advice - its in safe levels and I should be thankful. I thought it might be a spike in CO2 so I opened some windows anyhow.

@intmug - I must admit I am ignorant of such things. I've basically lived in Cali for most of my life; its very temperate there and we often keep the windows open all the time. So the idea that a house could be so insulated that it traps CO2 is a blindside.

The place I rent is on the beach, its old. Probably circa 1950's - made of thick block - a shotgun type place with 6 units facing north, running east to west. One two bedroom (mine) and four studios. The AC unit is located in one of my bathrooms - its central ac only for my unit. And as far as a thermostat it's a analog dial - no idea what a humidistat is but I'm pretty sure I don't have it unless its inside the ac unit. All appliances are electric.

I will make some calls on Monday to see if I can get someone with a CO2 meter here.

Reefers4U
07/13/2014, 11:44 AM
UPDATE:

Here is a screenshot from my controller. The airline, by itself wasn't doing the trick, although it had a noticeable effect - the start of the data represents the date it was installed. You can see an initial period of increase out of the danger zone but barley able to maintain and then an eventual slow decline starting July 7th.

On July 9th I installed a fan on the window of the room the tank is in and let it run overnight.

Now I'm seeing great numbers and even the pH rise off cycle. I noticed that my Alk had fallen a little (still within acceptable numbers) and that my Calc was low so the spikes you see are a result of adding kalk to the sump. I've now got it so that Kalk gets added with ATO water.

Hopefully these numbers hold and I can start getting some coral again.

Randy Holmes-Farley
07/14/2014, 05:20 AM
:thumbsup:

Good luck. :)

sunny d polyp
07/15/2014, 06:31 AM
Why are you chasing your pH?

Reefers4U
07/15/2014, 02:52 PM
please read the entire thread.

my corals died because the pH was too low. I hardly think thats "chasing" pH.

sunny d polyp
07/16/2014, 05:02 AM
I never test my PH, I keep my salinity, ca, alk and mg at NSW parameters and it just works out.

Randy Holmes-Farley
07/16/2014, 05:14 AM
I never test my PH, I keep my salinity, ca, alk and mg at NSW parameters and it just works out.

That's fine for you, and may work for many or even most people, but you should recognize that pH is controlled by the CO2 in your home air. If yours and mine are OK is not a reason to assume that everyone else's must be. CO2 in homes varies tremendously, and as pH values drop below 8, calcifying organisms spend more and more energy trying to lay down skeletons. If the pH drops low enough, those skeletons will slowly dissolve.

This is a huge concern for marine biologists studying coral reefs as CO2 rises from burning of fossil fuels, and the effects inside homes can be far worse than outside. :)

sunny d polyp
07/16/2014, 05:35 AM
Hey Randy and glad youíre here, I've heard that scenario before and understand the fact but if the C02 level was high enough to cause the ph to drop in the tank wouldn't that scenario cause the people in the house to show signs of an imbalance too? I'm a facility manager and we are always concerned about C02 levels in our buildings (keeps everyone awake and productive for the most part) so I have a HVAC controls system that increases the 02 levels automatically through our outside dampers. I donít know of anyone that does it but I know we have the technology (not sure how expensive it is for the average hobbyist) but if the levels were high of C02 could we add additional 02 through the skimmer or a bubble counter counter to help? Kind of like people add C02 to planted tanks? Thanks for your reply and I appreciate all the help I can get with this hobby, I couldnít do it without forums, people like you and of course a credit card (oh yea a wife that understands too).

Jerry S.

Randy Holmes-Farley
07/16/2014, 06:07 AM
I've heard that scenario before and understand the fact but if the C02 level was high enough to cause the ph to drop in the tank wouldn't that scenario cause the people in the house to show signs of an imbalance too?

OSHA limits CO2 in the workplace to 5,000 ppm for long periods and 30,000 ppm for short periods. Presumably, the effects on people at 1,000 -2,000 ppm are not that significant, but I'd want fresher air.

At 5,000 ppm (12.8 times the outside level of about 390 ppm today), the pH of seawater in equilibrium with that air is about a full 1.1 pH units lower than it would be if it were in equilibrium with normal air. That level (about pH 7) is low enough to dissolve aragonite.

Most people don't have nearly that much CO2 in their homes, but values of 1,000-2,000 are not that unusual. Each doubling of the CO2 level drops pH by about 0.3 pH units.

FWIW, adding O2 doesn't help, unless you add so much that you sweep away some of the CO2. :)

tmz
07/16/2014, 06:46 AM
The OP reported pH below 7.7 which is the point at which calcium carbonate including the aragonite in skeletal mass can begin to dissolve.

CO2 effects for humans relate to a reduced ability of hemoglobin to transport oxygen when high levels of CO2 as CO2 are in the blood.This is sometimes the case for folks with lung disease even at atmospheric levels of CO2, around 400ppm.

Typically health standards for indoor air range upwards of 1,000ppm. This is from the Minnestota Dep't pf Health, fyi:

http://www.health.state.mn.us/divs/eh/indoorair/co2/

From it:

Carbon dioxide is not generally found at hazardous levels in indoor environments. The MNDOLI has set workplace safety standards of 10,000 ppm for an 8-hour period and 30,000 ppm for a 15 minute period. This means the average concentration over an 8-hour period should not exceed 10,000 ppm and the average concentration over a 15 minute period should not exceed 30,000 ppm.

People are equipped to manage CO2 levels via the venous system and lungs . On the other hand much lower increases in hydrolized CO2 in a reef tank or the sea can have a significant effect on overall acidity and pH. In water the negative effects of high CO2 relate to the extra H+ it adds .CO2 doesn't displace oxygen transport or vice versa
like it does in hemoglobin.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has developed ventilation guidelines that should maintain a comfortable environment for most occupants......
These rates of ventilation should keep carbon dioxide concentrations below 1000 ppm and create indoor air quality conditions that are acceptable to most individuals.

tmz
07/16/2014, 07:00 AM
FWIW, I keep pH in the 8.15 to 8.4 range, daily swing, in my aquariums but don't do it by raising raising alkalinity . IMO the "don't chase pH" theme is a bit too trendy these days. While tanks can do very well at at bottom level of 7.8, the higher levels of H+ high CO2 brings vs to sea water levels are not ideal for marine organisms ,particularly those that calcify ,imo.

sunny d polyp
07/16/2014, 08:37 AM
Now that is what I love about this forum, the wealth of knowledge that our members possess. Thank you for the explanation.
Jerry S.

Reefers4U
09/14/2014, 10:38 AM
UPDATE:

So my pH has been above 7.8 now since installing a fan on my window. Installed 6/1/14.

I just went to target and got one of those $20 floor fans and put it on the outside of my window. I lost so much coral trying to figure out the problem its discouraging to think $20 could have saved me a lot.

But if you are having the same problem keeping pH up because of gas exchange in your house - try taking a smaller fan, placing it in the window and attaching it to a skimmer airline - maybe try a make-shift funnel to direct the air from the fan into the airline.

I find that when I place the skimmer's air line into the fan's exhaust/output it really keeps the pH steady at 8.0 off cycle.

HTH

maybe someone smarter than I can weigh in on the science behind all this.

Thanks to RHF (and everyone else who viewed or responded) for being a responsive contributor to my post.