PH question

BlueFish · 06-28-2012, 06:57 PM

Hi - I am stumped by this PH question . ..
Background: I have 50 gallon, heavily planted tank with a heavy fish load. I am running T5s with plenty of light. There is a pressurized CO2 system with a solenoid and PH monitor. The solenoid is plugged into a power strip that alternates current from day to night. The lights and solenoid are plugged into the daytime side, and air pump on the night side. My canister filter and ciculation pump are on 24/7. It has been up and running beautifully for 1 year, the CO2 system for about 4 months. Everything is thriving. The PH would swing from 7.2 in the morning before the lights and solenoid come on after aerating all night, to 6.2 at the end of the light cycle.

Problem: For the past week I have noticed that the PH monitor has read 6.3 or 6.4 all the time - morning, noon, and night. This doesn't seem right or even possible to me. I checked and the solenoid is working properly in that if I force it to come on by changing the "alert" setting, it does come on. If the canister was out of C02, wouldn't the PH be high all the time, not low?

What might cause the low PH? I did a large water change last weekend but I use RODI water and condition it with a product to correct the PH . ..

Any ideas?
Thanks in advance. If I didn't give enough info, just ask.

**kangshiang** · 06-28-2012, 07:15 PM

CO2 will lower your PH for sure.

pejerrey · 06-28-2012, 07:17 PM

My monitor run out of batteries once and gave me odd readings. Unfortunately, I started messing with other things before changing the batteries. Is yours battery operated?

I wouldn't worry either way that is good ph IMO, stable? Awesome!
Unless you have some critter that need the ph swings? I doubt it.
*~*

**Complexity** · 06-28-2012, 07:38 PM

Quote:

Originally Posted by BlueFish

I checked and the solenoid is working properly in that if I force it to come on by changing the "alert" setting, it does come on.

Did you check to be sure the solenoid isn't stuck open? Make sure it will go off when you unplug it.

If that's working, then clean and recalibrate the pH probe.

Do you have a drop checker in the tank? If so, is the color changing or remaining the same?

BlueFish · 06-28-2012, 07:39 PM

kangshiang - yes, CO2 will lower it, but shouldn't it go back up overnight with aeraton?

pejerrey - interesting thougtht - I will check the batteries when I get home.
It is not really a problem, but what made me check it in the first place was that I had not seen "pearling" for a little bit - maybe a week or two. so I was checking to make sure I had not run out of CO2. It surprised me that the reading was so low without seeing the pearling on my groundplants.

BlueFish · 06-28-2012, 07:43 PM

Hi Vicky - I believe the solenoid is not stuck since when it comes on the red light blinks then goes off when it shuts off. I do have a drop checker and it has been a steady green, but recalibrating all instruments is a very good suggestion. Thanks.

jstehman · 06-28-2012, 09:52 PM

Did you check your PH with a liquid test?

**Complexity** · 06-28-2012, 11:19 PM

Quote:

Originally Posted by BlueFish

Hi Vicky - I believe the solenoid is not stuck since when it comes on the red light blinks then goes off when it shuts off. I do have a drop checker and it has been a steady green, but recalibrating all instruments is a very good suggestion. Thanks.

The light only refers to your pH controller, not the solenoid.

Do you hear an audible "click" when the solenoid goes on and off?

Do you have a bubble counter on your regulator, and if so, do the bubbles stop when the solenoid shuts off?

PlantedRich · 06-29-2012, 12:14 AM

I agree that there should be a click but I also found that can mislead you. My solenoid was stuck but I could hear a click. There is a spring in mine which was moving even though the metal valve body itself was frozen. Look for a change in the bubble stream to be sure.

BlueFish · 06-29-2012, 07:27 PM

Thanks for all the great suggestions.
The solenoid does click when forced on by manipulating the ph monitor (which is plugged in and not with batteries). I do not have a bubble counter on the system right now, but I have located one at my LFS and will pick it up tomorrow and install. Than will hellp me figure out what's going on. On closer inspection I see that the tubing from the CO2 canister to the reactor chamber is compressed as though with suction. weird.
I will post after the bubble counter is installed with an update.

At least fish and plants are doing ok. the plants should be pearling and they are not. but they are not in any immediate danger.

**Complexity** · 06-29-2012, 08:04 PM

Do you have a check valve between the regulator and the reactor?

BlueFish · 06-29-2012, 08:07 PM

Yes. but when I disconnected the line from the solenoid and blew into it, I was not able to get much air through the line.
But I am still baffled why the PH was at 6.3 and not 7.2 this was at 7am this morning after no lights and aerating all night.
I will get a new PH test kit tomorrow, too. I am missing something.

06-28-2012, 06:57 PM	#1
BlueFish Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: Sep 2008 Location: Hudson, NH Posts: 8	PH question Hi - I am stumped by this PH question . .. Background: I have 50 gallon, heavily planted tank with a heavy fish load. I am running T5s with plenty of light. There is a pressurized CO2 system with a solenoid and PH monitor. The solenoid is plugged into a power strip that alternates current from day to night. The lights and solenoid are plugged into the daytime side, and air pump on the night side. My canister filter and ciculation pump are on 24/7. It has been up and running beautifully for 1 year, the CO2 system for about 4 months. Everything is thriving. The PH would swing from 7.2 in the morning before the lights and solenoid come on after aerating all night, to 6.2 at the end of the light cycle. Problem: For the past week I have noticed that the PH monitor has read 6.3 or 6.4 all the time - morning, noon, and night. This doesn't seem right or even possible to me. I checked and the solenoid is working properly in that if I force it to come on by changing the "alert" setting, it does come on. If the canister was out of C02, wouldn't the PH be high all the time, not low? What might cause the low PH? I did a large water change last weekend but I use RODI water and condition it with a product to correct the PH . .. Any ideas? Thanks in advance. If I didn't give enough info, just ask.

06-28-2012, 07:17 PM	#3
pejerrey Wannabe Guru (View User Tanks) PTrader: (12/100%) Join Date: Dec 2011 Location: Oakland, California Posts: 1,924	My monitor run out of batteries once and gave me odd readings. Unfortunately, I started messing with other things before changing the batteries. Is yours battery operated? I wouldn't worry either way that is good ph IMO, stable? Awesome! Unless you have some critter that need the ph swings? I doubt it. ~ __________________ *A heavily planted shrimp tank is possible!*

06-28-2012, 09:52 PM	#7
jstehman Planted Tank Obsessed (View User Tanks) PTrader: (0/0%) Join Date: Dec 2010 Location: LaVista, NE Posts: 342	Did you check your PH with a liquid test? __________________ Never show anyone your true potential. If you do, they will always expect it.

06-29-2012, 08:04 PM	#11
Complexity Pelvicachromis Lover! (View User Tanks) PTrader: (34/100%) Join Date: Jan 2008 Location: Houston, TX Posts: 5,058	Do you have a check valve between the regulator and the reactor? __________________ Vicki —Rena Filstar pimp #142 (four XP4s/three XP2s/one XP1) • Eheim pimp #301 (Pro II 2128) • Victor pimp #27 (VTS-253B-320) • 90g - Journal Pelvicachromis taeniatus 'Moliwe' —— • 75g - Journal Pelvicachromis pulcher 'Lagos Red' Better Pics 8-24 • 29g - Journal Pelvicachromis pulcher 'unknown' —-- • 29g - Pelvicachromis taeniatus 'Moliwe' • 5g - RCS colony —————————————————— • 2.5g - Journal Retired

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06-28-2012, 07:15 PM	#2
kangshiang Planted Tank Obsessed (View User Tanks) PTrader: (130/99%) Join Date: Jun 2006 Location: Los Angeles Posts: 451	CO2 will lower your PH for sure.

06-28-2012, 07:39 PM	#5
BlueFish Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: Sep 2008 Location: Hudson, NH Posts: 8	kangshiang - yes, CO2 will lower it, but shouldn't it go back up overnight with aeraton? pejerrey - interesting thougtht - I will check the batteries when I get home. It is not really a problem, but what made me check it in the first place was that I had not seen "pearling" for a little bit - maybe a week or two. so I was checking to make sure I had not run out of CO2. It surprised me that the reading was so low without seeing the pearling on my groundplants.

06-28-2012, 07:43 PM	#6
BlueFish Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: Sep 2008 Location: Hudson, NH Posts: 8	Hi Vicky - I believe the solenoid is not stuck since when it comes on the red light blinks then goes off when it shuts off. I do have a drop checker and it has been a steady green, but recalibrating all instruments is a very good suggestion. Thanks.

06-29-2012, 12:14 AM	#9
PlantedRich Wannabe Guru (View User Tanks) PTrader: (0/0%) Join Date: Jul 2010 Location: Pflugerville, Tx Posts: 1,513	I agree that there should be a click but I also found that can mislead you. My solenoid was stuck but I could hear a click. There is a spring in mine which was moving even though the metal valve body itself was frozen. Look for a change in the bubble stream to be sure.

06-29-2012, 07:27 PM	#10
BlueFish Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: Sep 2008 Location: Hudson, NH Posts: 8	Thanks for all the great suggestions. The solenoid does click when forced on by manipulating the ph monitor (which is plugged in and not with batteries). I do not have a bubble counter on the system right now, but I have located one at my LFS and will pick it up tomorrow and install. Than will hellp me figure out what's going on. On closer inspection I see that the tubing from the CO2 canister to the reactor chamber is compressed as though with suction. weird. I will post after the bubble counter is installed with an update. At least fish and plants are doing ok. the plants should be pearling and they are not. but they are not in any immediate danger.

06-29-2012, 08:07 PM	#12
BlueFish Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: Sep 2008 Location: Hudson, NH Posts: 8	Yes. but when I disconnected the line from the solenoid and blew into it, I was not able to get much air through the line. But I am still baffled why the PH was at 6.3 and not 7.2 this was at 7am this morning after no lights and aerating all night. I will get a new PH test kit tomorrow, too. I am missing something.