plebian
Fish Fanatic
I am an advocate of undergravel filters. I equipped my first aquarium, more than 30 years ago, with a UGF. Initially I was attracted by the price, but over time I learned to appreciate their reliability and efficiency.
Recently, I lost all my discus due to a massive microbial bloom that absorbed all the oxygen in the water. I was attempting to rid the discus of flukes using praziquantel dissolved in alcohol, not aware at the time of any warnings concerning the use of alcohol and microbial blooms.
I decided to sterilize my aquarium before purchasing any more discus. First, I filled the aquarium to just above the previous waterline. Then I added enough bleach to produce a solution of 60 ppm, allowing it to sit overnight. I left the fully submerged powerheads running so the bleach solution would pass through the UGF.
Once the aquarium was sterilized, I drained and refilled it, chemically neutralizing the remaining chlorine residue. I then started the nitrogen cycle by adding some ammonium sulfate to the aquarium. Once the UGF began breaking down the ammonia, I purchased a group of 5 juvenile discus.
Since the local water has a pH of 7.7, I wasn’t too concerned about nitrite, which is not nearly as toxic as ammonia given this pH. Also, I do not believe in heavy stocking, so I decided to complete the nitrogen cycle with the newly purchased discus.
This is my experience cycling an aquarium with discus and UGF filtration.
Just over 3 months ago, after sterilizing the aquarium, I added enough ammonium sulfate to produce 6 ppm of ammonia. My water parameters at that time were as follows:
pH = 7.7
GH = 255 ppm
KH = 204 ppm
Ca = 100 ppm
Mg = 36 ppm
The TDS meter measured 350 ppm.
The TDS reading was surprising, since the local water source is generally stable at around 280 ppm.
Note the difference between the GH and the Ca and Mg readings. Ca and Mg should add up to GH, but they don’t. I have more confidence in the Ca and Mg tests since they are very specific. All the tests are from the same manufacturer, so I can only assume the GH test is capturing one or more additional minerals.
Also notice the discrepancy between GH and TDS. This is not surprising. TDS meters actually measure dissolved ions and will therefore capture other ionic compounds in addition to Ca and Mg, the most common being sulfate. While I did add sulfate to the water, it was not nearly enough to account for the discrepancy. This suggests the local water source contains a substantial amount of sulfate as well as Ca and Mg.
Seven days after adding the ammonium sulfate I finally got a nitrite reading of 0.25 ppm, indicating ammonia was finally being processed.
The following morning I changed out 80% of the water, which reduced ammonia to 0.5 ppm and nitrite to 0.2 ppm. In the afternoon, I added 5 juvenile discus (2.5 inches) to the aquarium. The following morning I measured ammonia at 0 ppm, as expected.
Two days after adding the discus, nitrite measured 1-2 ppm. I added enough salt to reduce the effective level of nitrite by 1 ppm purely as a precaution, since nitrite at this level and pH is not toxic. The following day, nitrite measured 1 ppm and nitrate measured 5 ppm, indicating that nitrite was now being processed and the nitrogen cycle was complete.
Four days after adding the discus, the nitrite level dropped to 0.5 ppm even though I had begun feeding the discus small amounts of food. This was confirmation that the microbial community colonizing the gravel was growing, so I began to increase feedings.
Two days later (six days after adding the discus) the nitrite level dropped to 0 ppm. I began weekly water changes of 50%, primarily to remove algae, since nitrates never exceeded 10 ppm.
Three months after sterilizing the aquarium, the water in the aquarium is now crystal clear. This is indicative of filtration with an established, diverse microbial population capable of maintaining excellent water quality. No specialized filter media, no water “polishing” and no chemicals necessary.
On a final note, I want to mention that I only vacuum the gravel when algae begins to colonize it, which is now about once a month. I do this strictly for aesthetic reasons. In the photo below, you are looking through 7.5 feet of water column.
Recently, I lost all my discus due to a massive microbial bloom that absorbed all the oxygen in the water. I was attempting to rid the discus of flukes using praziquantel dissolved in alcohol, not aware at the time of any warnings concerning the use of alcohol and microbial blooms.
I decided to sterilize my aquarium before purchasing any more discus. First, I filled the aquarium to just above the previous waterline. Then I added enough bleach to produce a solution of 60 ppm, allowing it to sit overnight. I left the fully submerged powerheads running so the bleach solution would pass through the UGF.
Once the aquarium was sterilized, I drained and refilled it, chemically neutralizing the remaining chlorine residue. I then started the nitrogen cycle by adding some ammonium sulfate to the aquarium. Once the UGF began breaking down the ammonia, I purchased a group of 5 juvenile discus.
Since the local water has a pH of 7.7, I wasn’t too concerned about nitrite, which is not nearly as toxic as ammonia given this pH. Also, I do not believe in heavy stocking, so I decided to complete the nitrogen cycle with the newly purchased discus.
This is my experience cycling an aquarium with discus and UGF filtration.
Just over 3 months ago, after sterilizing the aquarium, I added enough ammonium sulfate to produce 6 ppm of ammonia. My water parameters at that time were as follows:
pH = 7.7
GH = 255 ppm
KH = 204 ppm
Ca = 100 ppm
Mg = 36 ppm
The TDS meter measured 350 ppm.
The TDS reading was surprising, since the local water source is generally stable at around 280 ppm.
Note the difference between the GH and the Ca and Mg readings. Ca and Mg should add up to GH, but they don’t. I have more confidence in the Ca and Mg tests since they are very specific. All the tests are from the same manufacturer, so I can only assume the GH test is capturing one or more additional minerals.
Also notice the discrepancy between GH and TDS. This is not surprising. TDS meters actually measure dissolved ions and will therefore capture other ionic compounds in addition to Ca and Mg, the most common being sulfate. While I did add sulfate to the water, it was not nearly enough to account for the discrepancy. This suggests the local water source contains a substantial amount of sulfate as well as Ca and Mg.
Seven days after adding the ammonium sulfate I finally got a nitrite reading of 0.25 ppm, indicating ammonia was finally being processed.
The following morning I changed out 80% of the water, which reduced ammonia to 0.5 ppm and nitrite to 0.2 ppm. In the afternoon, I added 5 juvenile discus (2.5 inches) to the aquarium. The following morning I measured ammonia at 0 ppm, as expected.
Two days after adding the discus, nitrite measured 1-2 ppm. I added enough salt to reduce the effective level of nitrite by 1 ppm purely as a precaution, since nitrite at this level and pH is not toxic. The following day, nitrite measured 1 ppm and nitrate measured 5 ppm, indicating that nitrite was now being processed and the nitrogen cycle was complete.
Four days after adding the discus, the nitrite level dropped to 0.5 ppm even though I had begun feeding the discus small amounts of food. This was confirmation that the microbial community colonizing the gravel was growing, so I began to increase feedings.
Two days later (six days after adding the discus) the nitrite level dropped to 0 ppm. I began weekly water changes of 50%, primarily to remove algae, since nitrates never exceeded 10 ppm.
Three months after sterilizing the aquarium, the water in the aquarium is now crystal clear. This is indicative of filtration with an established, diverse microbial population capable of maintaining excellent water quality. No specialized filter media, no water “polishing” and no chemicals necessary.
On a final note, I want to mention that I only vacuum the gravel when algae begins to colonize it, which is now about once a month. I do this strictly for aesthetic reasons. In the photo below, you are looking through 7.5 feet of water column.
