The critical steps to maintaining a healthy aquaponics system
By Phil Bishop, Stuppy Greenhouse
"I use the process of looking at the system as a whole, then in smaller sections and finally each individual component. By going through this analysis each day I am able to stay ahead of any changes that may be starting that I want to either stop or let continue.
As I first approach the system I walk around it looking from top to bottom. Questions that I need to answer: are the air and water pumps running, is there any water on the ground from possible leaks and in our case are the grow lights on. I also view the plant growth as a whole. The plants should be upright and each row showing similar growth patterns.
The next part is going tank by tank and looking at their functions. Starting with the fish tank, I’m looking at the fish and their behavior. When the fish are first added their behavior is sporadic because they are not used to the system but key things to look for are if they are rubbing their sides on the bottom of the tank, which could be a sign of a disease or pest, or gasping for air out of the water, a sign of low oxygen. As the fish get used to being in the tank and seeing people they will come to the top expecting food.
Water level in the fish tank is very important and should always be at the same point in the tank. If the water level is above or below its usual point means there is a blockage or the water pump is not functioning on some level. In the fish tank I also look at the amount of fish waste. There will always be some at the bottom but it shouldn’t be built up into piles. If the system is running correctly the waste will continuously be pulled up through the stand pipe in the fish tank. If there is waste built up it means the water coming into the fish tank is not entering at a high enough rate to make the water rotate and pull the waste to the center of the tank and up the stand pipe. Again, this would be a function of the water pump or a possible blockage in the pipe.
Moving to the media bed I first watch the water coming from the fish tank. Over time you will be able to see if the flow rate is off but if the fish tank water level is normal the flow rate into the media bed should also be normal. Next I watch the bell siphon to make sure it engages and drains the water from the tank. Another sign the flow rate is incorrect is if the siphon doesn’t engage. This would be due to too high or too low of flow rate of the water coming into the media bed. Again, looking at the plant growth as a whole I look for patterns and also germination rates if we are seeding new plants.
The float bed water, just like the fish tank, needs to be continuously at the same level. The water is pumped from the sump tank to the float bed and drains from the float bed to the fish tank. If the water level is off it is due to the pump needing to be adjusted or a blockage in the drain pipe to the fish tank.
The sump tank is the lowest point in the system and the best place to verify the amount of water in the system. The fish tank and float bed have stable water levels but the media bed and sump tank change as the water is pumped from the sump tank to the float bed and the media bed fills and drains to the sump tank. As I watch the media bed drain I also make note of the low level of the sump tank and the high level, after the media bed is completely drained. If the system needs water added this is the only place to get this reading. Water will mostly likely need to be added each week.
Final analysis level is the individual components and by this I mean the plants, fish and bacteria. First I look over each plant, looking at leaf color, presence of pests or diseases and shape of the plant. In the float bed I lift up the rafts to see the roots. They should be clean and white.
For the fish I pull out ten percent to get their average weight and length. I only get their measurements once a week to minimize stress but I am also doing this as part of food and growth research. These measurements directly correlate to the amount of food the fish receive daily. If needed I adjust the automatic feeder to the updated rates. Daily I make sure the feeders are full of food and working correctly.
The last step is testing the water. The testing is the way I can determine if the bacteria colonies are healthy. This step is done once a week once the system is cycled. During cycling water was tested once a day. The water tests give readings of ammonia, nitrites and nitrates. I am looking for very little to no ammonia, little to no nitrites and elevated nitrates. If the test read something different then the bacteria colonies have been compromised somehow.
By going over the system each day in this manner we are able to run a healthy system and react to changes in a timely manner. Just as putting clean water and plants into the system regulates the health of the system so does a methodical approach to analysis and maintenance of the Aqueduct. Our other blog posts go more in depth on each of these topics and if you have more questions they are a good resource.
More information on Aquaponic systems:
For more information:
Stuppy Greenhouse Manufacturing
Phil Bishop
(800) 733-5025 FREE
[email protected]
www.stuppy.com