hillrc91
07/07/2004, 11:02 AM
Randy,
In the past, I have benefited greatly from your articles. In order to give you the clearest possible picture of my situation, I have provided detailed information below concerning the problem, the equipment I use, my current water parameters, and a full description of my failed attempts to resolve the issue.
Put simply, like some other recent posts that I've seen, my PH is chronically low, usually in the range of 7.92 to 7.96. (Measured with a properly calibrated Hanna Instruments PH meter.)
Attempting to maintain PH 8.2 (or anything approaching that level) in my 45G FOWLR seems to be nearly impossible.
My first attempt to rectify the problem was to add powerheads to provide vigorous surface agitation and circulation. Since most gas exchange occurs at the surface, I added 2 marineland penguin 1140's, for surface agitation, and two hagen aquaclear 301's for circulation around the live rock. There has not been an impact.
My second action was an experiment of sorts... Acting on advice, and a written article or two, I wanted to determine if CO2 buildup within my home was the source of the problem. I took 1/2 gallon of water out of the tank, placed it in a bucket, and aerated it outdoors for 24 hours. On that particular day, my PH reading was lower than normal, at 7.82. After 24 hours, the sample PH increased to 8.06. Problem solved? Not really.
As a result of this experiment, I opened all the windows near the tank in order to decrease CO2 levels, and increase oxygen. (Thereby increasing PH) The windows remained open for a week. This also had no effect.
My third attempt was to increase alkalinity using a buffer product by Seachem. While the buffer raised the PH, the effect was only temporary. A case in point: I recently used the buffer to increase PH from 7.92 to 8.11. Within 7 hours, the PH was back down to 7.93. With my alkalinity reading at 6.5 Meq/l, I believe that further additions of buffer would have been ineffectual, and may cause calcium to precipitate.
My fourth attempt was to use a Kalkwasser supplement. It's effect was similar to using a buffer. --The PH temporarily rose, and then dropped down to it's original level within several hours.
My fifth attempt was to buy a small fan, and place it over the aquarium. This had no effect, other than to cause a large amount of evaporation.
Up until this point, I had used a Tetra D.O. test. The results of the test indicated that my D.O. level was somwhere above 5ppm, but not quite 8ppm. (My best guess at reading the color chart.)
Last week I bought a Pinpoint II Dissolved Oxygen meter... After properly calibrating the meter, I was shocked to see a reading of 7.5-7.6ppm (depending upon how deep the meter was placed) My understanding is that 100% Oxygen saturation in marine aquaria is somewhere around 6.9ppm (depending upon temperature and salinity factors) I've also read that a condition called "supersaturation" can exist around vigorously aerated areas.. I don't know if this is occuring.... Yet my PH is still stagnant at 7.93.
I have tried using a different salt mix.... Normally I use Reef Crystals, but because it typically only mixes up to PH 8.0- (max 8.1 on a good day) I tried using Seachem's Reef Salt. The Seachem salt mixes up to PH 8.51-8.54. After adding it to the aquarium during a partial water change the PH went from 7.95 to 8.18----and then back down to 7.92 in 9 hours.
The D.O. meter (if accurate) measures anywhere from 8.1-8.4ppm in my source water (tap).
My equipment is as follows:
45G High FOWLR Tank
20LBS Fiji Live Rock
3.5 inch Deep Sand Bed
Red Sea Prizm Protein Skimmer
2 Magnum 350 Canister filters (one for dedicated Chemical Filtration,(Kent Reef Carbon and Phosphate/Silicate Remover) the other for Mechanical (Magnum micron cartridge)
1 Penguin 170 Biowheel filter.
Aeration and Circulation: I have a total of 4 powerheads, (Two Marineland Penguin 1140's providing vigorous surface agitation, and two Hagen Aquaclear 301's for circulation around the live rock.).
Water Parameters: (Measured with a digital colorimeter accuracy)
Temperature 76.1
PH: 7.93 (Measured with a PH meter)
Alkalinity 6.5 meq/l
Ammonia: 0.09 ppm
Nitrite: 0.0 ppm
Nitrate 18.6 ppm
S.G. 1.023
Phosphate: 0.39 ppm
Silicate: 0.2 ppm
Dissolved Oxygen: 7.5-7.6ppm. (Measured with a properly calibrated Pinpoint II D.O. Meter)
Water Changes: 30% water change performed every 2 weeks using Reef Crystals salt. The source water used for these changes has mostly been tap (very good tap water quality where I live) but I have tried RO/DI with no effect on PH.
Fish: 4 Small 1-2 inch fish.
Feeding: Twice Daily. Just enough to consume within 2 minutes. Various flakes and pelets.
What am I missing here?
Richard
In the past, I have benefited greatly from your articles. In order to give you the clearest possible picture of my situation, I have provided detailed information below concerning the problem, the equipment I use, my current water parameters, and a full description of my failed attempts to resolve the issue.
Put simply, like some other recent posts that I've seen, my PH is chronically low, usually in the range of 7.92 to 7.96. (Measured with a properly calibrated Hanna Instruments PH meter.)
Attempting to maintain PH 8.2 (or anything approaching that level) in my 45G FOWLR seems to be nearly impossible.
My first attempt to rectify the problem was to add powerheads to provide vigorous surface agitation and circulation. Since most gas exchange occurs at the surface, I added 2 marineland penguin 1140's, for surface agitation, and two hagen aquaclear 301's for circulation around the live rock. There has not been an impact.
My second action was an experiment of sorts... Acting on advice, and a written article or two, I wanted to determine if CO2 buildup within my home was the source of the problem. I took 1/2 gallon of water out of the tank, placed it in a bucket, and aerated it outdoors for 24 hours. On that particular day, my PH reading was lower than normal, at 7.82. After 24 hours, the sample PH increased to 8.06. Problem solved? Not really.
As a result of this experiment, I opened all the windows near the tank in order to decrease CO2 levels, and increase oxygen. (Thereby increasing PH) The windows remained open for a week. This also had no effect.
My third attempt was to increase alkalinity using a buffer product by Seachem. While the buffer raised the PH, the effect was only temporary. A case in point: I recently used the buffer to increase PH from 7.92 to 8.11. Within 7 hours, the PH was back down to 7.93. With my alkalinity reading at 6.5 Meq/l, I believe that further additions of buffer would have been ineffectual, and may cause calcium to precipitate.
My fourth attempt was to use a Kalkwasser supplement. It's effect was similar to using a buffer. --The PH temporarily rose, and then dropped down to it's original level within several hours.
My fifth attempt was to buy a small fan, and place it over the aquarium. This had no effect, other than to cause a large amount of evaporation.
Up until this point, I had used a Tetra D.O. test. The results of the test indicated that my D.O. level was somwhere above 5ppm, but not quite 8ppm. (My best guess at reading the color chart.)
Last week I bought a Pinpoint II Dissolved Oxygen meter... After properly calibrating the meter, I was shocked to see a reading of 7.5-7.6ppm (depending upon how deep the meter was placed) My understanding is that 100% Oxygen saturation in marine aquaria is somewhere around 6.9ppm (depending upon temperature and salinity factors) I've also read that a condition called "supersaturation" can exist around vigorously aerated areas.. I don't know if this is occuring.... Yet my PH is still stagnant at 7.93.
I have tried using a different salt mix.... Normally I use Reef Crystals, but because it typically only mixes up to PH 8.0- (max 8.1 on a good day) I tried using Seachem's Reef Salt. The Seachem salt mixes up to PH 8.51-8.54. After adding it to the aquarium during a partial water change the PH went from 7.95 to 8.18----and then back down to 7.92 in 9 hours.
The D.O. meter (if accurate) measures anywhere from 8.1-8.4ppm in my source water (tap).
My equipment is as follows:
45G High FOWLR Tank
20LBS Fiji Live Rock
3.5 inch Deep Sand Bed
Red Sea Prizm Protein Skimmer
2 Magnum 350 Canister filters (one for dedicated Chemical Filtration,(Kent Reef Carbon and Phosphate/Silicate Remover) the other for Mechanical (Magnum micron cartridge)
1 Penguin 170 Biowheel filter.
Aeration and Circulation: I have a total of 4 powerheads, (Two Marineland Penguin 1140's providing vigorous surface agitation, and two Hagen Aquaclear 301's for circulation around the live rock.).
Water Parameters: (Measured with a digital colorimeter accuracy)
Temperature 76.1
PH: 7.93 (Measured with a PH meter)
Alkalinity 6.5 meq/l
Ammonia: 0.09 ppm
Nitrite: 0.0 ppm
Nitrate 18.6 ppm
S.G. 1.023
Phosphate: 0.39 ppm
Silicate: 0.2 ppm
Dissolved Oxygen: 7.5-7.6ppm. (Measured with a properly calibrated Pinpoint II D.O. Meter)
Water Changes: 30% water change performed every 2 weeks using Reef Crystals salt. The source water used for these changes has mostly been tap (very good tap water quality where I live) but I have tried RO/DI with no effect on PH.
Fish: 4 Small 1-2 inch fish.
Feeding: Twice Daily. Just enough to consume within 2 minutes. Various flakes and pelets.
What am I missing here?
Richard