This week I am finishing building my biofilter and will be researching methods for fish capture and handling.
The biofilter design I chose uses a system where water flows into the bottom of a five gallon bucket and out the top. This will force the water up through my filter material instead of splashing down on top of it which could potentially harm the bacteria the system will produce. During my testing of this design I encountered a problem where the water entering the bucket was far more than the water exiting the top of the bucket creating a high pressure in the system and causing leaks. This will hopefully be solved on my second attempt with a larger exit hole for the water at the top. The finished working biofilter should be completed by next week.
My project to estimate the population of the goldfish pool is continuing with more research into the methods and fish capture techniques. From my research so far I will most likely be using the Chapman estimator which is a modified form of the Lincoln-Petersen method. The Lincoln-Petersen method is a simple equation where the number of fish caught (and marked) on the first sample is multiplied by the number caught on the second sample and then divide by the number of fish in the second sample that have been marked. I will be using the Chapman estimator because it produces a less biased estimate with smaller sample sizes.