Stuppy Aquaponics Blog

By: Conor Quinlan

Water Quality Overview:  After only one week there is already a significant change in the water quality parameters. Mainly the ammonia and nitrite levels have risen dramatically. This means that bacteria responsible for the conversion of ammonia to nitrite are present. The nitrate levels are

PROTOTYPE CLARIFIER:

(11/18) The prototype clarifier has finally been added to our research system and should clear up the waste build up in the media bed thus improving its water retention, nitrification, overall cleanliness and life cycle. Below is an image of the prototype; it is a radial style clarifier with a partially submerged outlet with multiple holes to keep clogging down. Submerging the output keep the flow rate more consistent over time.

The research system has been run continuously for a year now without a clarifier and the media bed has built up enough waste to block off around

By: Conor Quinlan

System Reset Overview: The system was officially re-filled on 12/19/16 (see deep cleaning post for details about cleaning procedure). The data from the initial startup is given above. Source water values were measured before adding to the system to gauge any change.

Cleaning removed a significant amount of all compounds however some ammonia and nitrate appears to have been left over, likely trapped in the media, as those values

By: Conor Quinlan

Water Quality: I have decided to push the parameters of the system again to observe how low the pH can get within a given feeding range. I have increased the feed amount from 150 grams feed per day to 240 mg feed per day over the past week and will not add CaCO₃ to increase pH until pH falls around 6.4. The increased feed and lower pH should also help the magnesium deficiency that has been observed in basil crops. Nitrification is proving to be more than sufficient, even at these lower pHs, thanks to the large surface area of the media bed. Now that the feeding rate has increase substantially it will also be interesting to see how nitrification performs over time.

A new, far more accurate, hardness test that uses titration as the chemical testing method was used to determine a more accurate estimate of the Mg concentration. The Mg concentration was lower than previous estimates however with a concentration of 55-67 mg/L that should be more than enough. Magnesium Sulfate was added to the system in very small amounts, only 25 grams for a total Mg concentration increase of 2 mg/L, to quicken the reverse of the Mg deficiency. This addition should help speed up recovery as the increased fish feed is processed and converted to nutrients.

Follow-Up:  

By: Conor Quinlan

Water Quality: Maintaining well. The system was finally drained and fully tested on Thursday. CaCO₃ was then added to determine how the parameters would be affected now that a significant portion of the system has been drained.

Follow-up:

By: Conor Quinlan

Water Quality: Maintaining very well. As expected the pH is now beginning to drop around an alkalinity of 25 mg/L. Seems to be a pretty effective indicator of when to add more CaCO3. As the alkalinity approaches 20 mg/L and drops below 6.5 more will be added. The 350 gram addition looks like it will last about a week. An insect called springtails was seen in the media bed today and likely contributed to the breakdown of organic material in the water.

New Information:

By: Conor Quinlan

Water Quality: Maintaining very well. The 350 gram addition of CaCO₃ is providing the stability that was expected. Alkalinity levels have dropped very fast over the weekend from 45 mg/L to 30 mg/L. Why this decreases so quickly at these slightly higher values is unknown but as the alkalinity gets lower the rate slows more and more until it seems to settle around 22-25 mg/L before more CaCO₃ needs adding.

The potassium test was received today, from salifert, and as far as I can tell it works with fresh water. Potassium will be tested weekly or so to determine if it is ever deficient. Besides Iron, potassium is the most limited nutrient generally in aquaponics

Follow Up:

By: Conor Quinlan

Water Quality: Maintaining very well. pH is still maintaining but closer to 6.5-6.4 now and alkalinity has still not dropped much. A 350 gram addition of CaCO₃ will be made today and a calcium and alkalinity test will be completed to get a better understanding of how much of the added CaCO₃ is dissolving. The 700 gram addition lasted 10 days, longer than anticipated.

New Information:

By: Conor Quinlan

Water Quality: Maintaining very well. pH reached the minimum of 6.5 this morning after 6 days of running with no additions. Despite the lower pH ammonia/nitrite concentrations remained very low over the holiday weekend signifying that nitrification was being performed at an acceptable rate. However nitrite concentrations did rise slightly from 0.25 -> 0.50 mg/L during this time and for this reason more CaCO₃ will be added today to bring both the pH and alkalinity back up.

Follow-Ups:

08/30/16

By: Conor Quinlan

Water Quality: Maintaining very well. pH is maintaining between 6.6 - 6.8, according to the probe which means the pH is continuing to maintain. I will continue to watch for changes in pH until the buffer is depleted then adjust the CaCO₃ addition to 375 g 1-2x per week

Follow-Ups: