Ph issues

[Gonzapa]

I am fighting low PH issues again and came up with what I think is a plan to figure out if excess CO2 is causing the problem.
I am going to mix a batch of salt and split it into 2 containers each with a maxijet for aereation.
I will place one outside and one inside next to my sump and leave them there for 24 hours.
I will then use my PH meter to measure the ph in both mixes.

I is my understanding that the difference in PH at this point would be due to the different amount of CO2 in the water. I the difference is extrmely high then I will have to figure out how to better aereate the tank with fresh air to raise PH ( I already have an air line from the outside going into the skimmer).


Are all my assumtions correct or I overlooking something here?

 

[hayabusa2003]

There's a mathematical relationship between Ph, Alkalinity, and CO2. If your Ph is low, then either you have low Alk, or high CO2. Check your Alk, if it's 7.0dKh or higher (depending on where you like to keep it), then your Ph problem is CO2.

Dripping Kalkwasser can help with low Ph issues.

What's your Ph, anyway?

Randy's article concerning the relationship between Ph and Alk ..
http://www.advancedaquarist.com/issues/may2002/chem.htm

 

[Gonzapa]

There's a mathematical relationship between Ph, Alkalinity, and CO2. If your Ph is low, then either you have low Alk, or high CO2. Check your Alk, if it's 7.0dKh or higher (depending on where you like to keep it), then your Ph problem is CO2.

Dripping Kalkwasser can help with low Ph issues.

What's your Ph, anyway?

Randy's article concerning the relationship between Ph and Alk ..
http://www.advancedaquarist.com/issues/may2002/chem.htm

Parameters are as follows SG 1.025 ALK 10.9 CA 450 MG 1400 PH 7.86

I have a calcium and a kalk reactor
Kalk is being used to replace evaporated water but lately (since summer started and the AC is on) my evaporation has dropped significantly so I cant replace enough water to get the ph up

If I take the kalk reactor offline then the ph drops as low as 7.56 during the night

 

[Jcurry@wesketch]

Calibrate your probe to verify it's measuring the Ph accurately. Also look to see if the probe wire is running to close to other wires (i.e. lights, pumps, etc.) I had "low" Ph readings until I noticed that the probe wire was running next to my lighting wires. I moved the probe location away from the other wires and and readings were fine.

 

[Gonzapa]

Calibrate your probe to verify it's measuring the Ph accurately. Also look to see if the probe wire is running to close to other wires (i.e. lights, pumps, etc.) I had "low" Ph readings until I noticed that the probe wire was running next to my lighting wires. I moved the probe location away from the other wires and and readings were fine.

I have 2 PH probes in the tank (one in the display tank upstair and one in the sump in hte basement) there is a difference of .02 between both of them so I know they are calibrated. Also If i put the Probe in refeence solution is spot on.

 

[hayabusa2003]

10.9kdh is ~ 3.93meq/l. According to Randy's chart, if your system is in equilibrium with the atmosphere, your Ph should be close to 8.4.

So the problem is either a testing error (which it sounds like it's not), or you have too much CO2 in your system.

Is the tank and/or sump near a window? if so, turn off the A/C and open the window to get more outside air in.

Is the surface water of the tank/sump being agitated? You need a lot of surface agitation to allow gas exchange from the system to the air around it. You can direct a powerhead up towards the surface to create more agitation.

If you set up a fan to blow over the sump, you'll evaporate water quicker and can top off more kalk, although I'd be careful with that since your dKh is already close to 11 and I'd be nervous about pushing it any higher.

I've also read where people put houseplants/greenery near the tank so that it will take up CO2. I don't know if a few houseplants would make any significant impact, but the theory makes sense.

Good luck, hopefully someone else who's had similar issues can chime in.

 

[Gonzapa]

10.9kdh is ~ 3.93meq/l. According to Randy's chart, if your system is in equilibrium with the atmosphere, your Ph should be close to 8.4.

So the problem is either a testing error (which it sounds like it's not), or you have too much CO2 in your system.

Is the tank and/or sump near a window? if so, turn off the A/C and open the window to get more outside air in.

Is the surface water of the tank/sump being agitated? You need a lot of surface agitation to allow gas exchange from the system to the air around it. You can direct a powerhead up towards the surface to create more agitation.

If you set up a fan to blow over the sump, you'll evaporate water quicker and can top off more kalk, although I'd be careful with that since your dKh is already close to 11 and I'd be nervous about pushing it any higher.

I've also read where people put houseplants/greenery near the tank so that it will take up CO2. I don't know if a few houseplants would make any significant impact, but the theory makes sense.

Good luck, hopefully someone else who's had similar issues can chime in.

Thw tank is neaar a window but opening makes no difference. I have left th ewindows open for the last 3 days with no change.

The sump is in the basement in the same room with the AC unit (whole house forced air)
I have powerheads on both the main tank and the sump agitating the water. I also have an asmg2 skimmer with the standard pump. The air intake is conected with tubing that draws air from the outside of the house.

The room where the sump is is on a corner of the basement with no windows so there is no way to get air in unless I drill holes and get tubbing through

 

[Jcurry@wesketch]

The sump is in the basement in the same room with the AC unit (whole house forced air)
..................... The air intake is conected with tubing that draws air from the outside of the house.

The room where the sump is is on a corner of the basement with no windows so there is no way to get air in unless I drill holes and get tubbing through

I think that the location of your sump might be the issue. It sounds like there might be a build up of CO2 in the sump room. Also were is the tubing from the skimmer exiting the house? Make sure it's not near the exhaust of your furnace. RichT had the same problem with the fresh air intake for his skimmer. It was located in an area that didn't get good air circulation and was collecting the CO2 from his furnace or water heater I forget which.

 

[Gonzapa]

Both the furnace and hot water heater and the sump are on the 10X10 room

 

[Gonzapa]

Ok I did the comparison over the weekend and the mixed water that was aereated inside the house for 4 days had a PH of 8.2. So I doubt that excessive CO2 is the issue.

 

[vangvace]

Was it aerated in the same room as the sump?

 

[Gonzapa]

Was it aerated in the same room as the sump?

Right next to the sump

 

[Jcurry@wesketch]

Ok I did the comparison over the weekend and the mixed water that was aereated inside the house for 4 days had a PH of 8.2. So I doubt that excessive CO2 is the issue.

Your test is flawed, aerating the water blows off the CO2 thus causing your Ph to rise. Try mixing the water in a bucket next to the sump and not aerating it and test the Ph. Then mix some water outside without aerating it and test the Ph. If they're both 8.2 then the problem isn't a build up of CO2 in the sump room.

 

[Gonzapa]

Ok I did the comparison over the weekend and the mixed water that was aereated inside the house for 4 days had a PH of 8.2. So I doubt that excessive CO2 is the issue.

Your test is flawed, aerating the water blows off the CO2 thus causing your Ph to rise. Try mixing the water in a bucket next to the sump and not aerating it and test the Ph. Then mix some water outside without aerating it and test the Ph. If they're both 8.2 then the problem isn't a build up of CO2 in the sump room.

I did not technically aereate it, I just had a pump for circulation

 

[Boomer]

Gonzapa

is my understanding that the difference in PH at this point would be due to the different amount of CO2 in the water. I the difference is extrmely high then I will have to figure out how to better aereate the tank with fresh air to raise PH ( I already have an air line from the outside going into the skimmer).

It may come up high room air CO2 just by those parameters you gave. However, it could also have been the high tank water CO2 from poor maintenance and have nothing to do with high room air what so ever.

I am going to mix a batch of salt and split it into 2 containers each with a maxijet for aereation.
I will place one outside and one inside next to my sump and leave them there for 24 hours.

This is all a waste of time and can be misleading


What you need to do take **tank water** and put some of it in a bucket and aerate it with an air pump for 8 hrs inside and take another bucket and do the same outside for 8 hrs. Then test the pH's and compare.


hayabusa

There's a mathematical relationship between Ph, Alkalinity, and CO2. If your pH is low, then either you have low Alk, or high CO2. Check your Alk, if it's 7.0dKh or higher (depending on where you like to keep it), then your Ph problem is CO2

True but a low Alk does not mean a low pH. It makes no difference what the Alk is. If CO2 enters the pH will drop despite any Alk high or low. You can have a pH of 8.3 with low Alk if the CO2 is also low. The Alk and CO2 dictate the pH i.e.,

Alk 4 meq/ l, CO2 0.64 ppm = pH 8.3

Alk 3 meq /l, CO2 0.48ppm = pH 8.3

Alk 2 meq /l, CO2 0.32 ppm = pH 8.3

Alk 1 meq/ l, CO2 0.16 ppm = pH 8.3

Std NSW @ 2.25 meq/, CO2 0.54 ppm CO2 = pH 8.15 and at pH 8.3 the CO2 is 0.36

According to Randy's chart, if your system is in equilibrium with the atmosphere, your Ph should be close to 8.4. [

True but tanks are rarely, if ever, in equilibrium with the atmosphere.

99 % of all pH issue in reef tanks or even the ocean are CO2.



Jcurry

Your test is flawed, aerating the water blows off the CO2 thus causing your Ph to rise. Try mixing the water in a bucket next to the sump and not aerating it and test the Ph. Then mix some water outside without aerating it and test the Ph. If they're both 8.2 then the problem isn't a build up of CO2 in the sump room.


This can be all misleading J, see above. You always aerate the water. If you aerate water indoors and have indoor CO2 issue the pH will drop in a fresh salt mix as the aeration is driving in CO2 and not out. If you let it just sit,as you suggested it takes to long, indoor or outdoor. You never test a new salt mix but tank water. If it is high tank CO2 and not air related then the aeration will raise the pH indoors = tank CO2 issue. If you aerate it outside = high room CO2 or high tank CO2. If you aerate the tank water indoors and the pH does not go up, then high room air CO2. You are suppose to be trying to "blow" off CO2 and raising the pH. That is what the test is all about and is always with tank water.

 

[Gonzapa]

boomer, I had had the windows open in the house for the last 3 days, and PH has not changed at all.
As far as maintenance I do a 10 % water change a week and remove the debris in the sump at least once a month.

 

[Boomer]

Well, you still have a CO2 issue or probe issue. A properly vented room and tank with good circulation and skimming, with good maintenance and properly cal probe, cannot have a pH of 7.86. Unless, your outside CO2 is much higher than anybody else's. Take a container of ** tank water and put it outside, with an air stone in it, running off an air pump and turn it up so the water is like "boiling" and check the pH in 8 hrs, with the meter and pH test kit. And watch what you see, the pH will have gone up into the low 8's.


NSW pH 8.1 - 8.3 @ ALK 10.9 dKH = 1.0647 - 0.6139 ppm CO2

NSW pH 7.86 @ ALK 10.9 dKH = 1.9862 ppm CO2

You are ~1 ppm CO2 to high

 

[Jcurry@wesketch]

" This can be all misleading J, see above. You always aerate the water. If you aerate water indoors and have indoor CO2 issue the pH will drop in a fresh salt mix as the aeration is driving in CO2 and not out. If you let it just sit,as you suggested it takes to long, indoor or outdoor. You never test a new salt mix but tank water. If it is high tank CO2 and not air related then the aeration will raise the pH indoors = tank CO2 issue. If you aerate it outside = high room CO2 or high tank CO2. If you aerate the tank water indoors and the pH does not go up, then high room air CO2. You are suppose to be trying to "blow" off CO2 and raising the pH. That is what the test is all about and is always with tank water."

Thanks Boomer I never thought about the fact that you could drive CO2 into the water from room the air. What would be the source of CO2 in the tank other than fish & corals? It seems to be unlikely that the inhabitants themselves could generate enough CO2 to lower the Ph that much as long as there is still circulating water.

 

[Boomer]

J

Over stocked tanks can generate allot of CO2 as can the break down of organics that give off CO2. All one has to do is look at an overstocked FOT where the CO2 is generated faster than it can leave. Circulation does not remove CO2 or even drive in O2 as much as one thinks, one needs to break the surface of the water with that circulation to drive off the CO2 and drive in that O2, just think skimmer as they seem to do a pretty good job of either or where water 'plunges' into the tank or a sump. Pretend you have a 50 gal tank with just a canister filter @ 600 gal and hr, that is a 12 x turn over but the effluent is under the surface of the tank water. No think the effluent is above the surface of the tank water,which will produce allot of turbulent. I know these are extremes but many tank do not have proper circulation. All on has to do is test the O2. If one looked at a well run FW planted tank you will see different CO2 levels all over the place using a CO2 meter and the same with a O2 meter. If you could do this for seawater you would see the same. I do not know if you know this or not j but even coral reefs at night have high CO2, where the pH drops and at times the O2 is at almost dangerous low levels, and it is the ocean and a reef yet.

 

[JRWOHLER]

Boomer excellent information thanks a ton. I don't want to hijack the thread by any means but can you expand on the last point you made?

do not know if you know this or not j but even coral reefs at night have high CO2, where the pH drops and at times the O2 is at almost dangerous low levels, and it is the ocean and a reef yet.

I do run my fuge on a reverse cycle to try and counteract it but I still see my PH drop at night. What would be a reasonable drop from say 8.1? Why some days does it drop more then others, CO2 in the room levels? Again thanks and hope this helps everyone on this topic.