Hello! I just want update you all about the changes I have made to my Aquaponics system. So, I’m going to post a graphic with the items I want to discuss numbered and I’ll talk about the points in order.
The first thing I want to discuss is a couple problems we had the system. As I noted my last blog post the first problem we had was that the standpipe was not perfectly vertical.
The problem is that if the standpipe is not perfectly vertical then the water surface is not perpendicular to the top of the standpipe. This means that as the water starts to flow into the standpipe, it doesn’t “overwhelm” the mouth of the pipe, causing a siphon to form. Because no siphon forms, the tank never drains. The system just simply continues to trickle water until you manually intervene.
The second problem we had was that as I noted the system is *heavy*. It’s so heavy, in fact, that we actually were starting to bend the shelving unit; particularlly the top shelf. This means that even if the standpipe had been properly installed, the water surface still would not have been perpendicular to the run of the pipe. As time went on the bow forming in the top shelf was becoming progressively more pronounced and I couldn’t leave the system run for more than 4 or 5 hours without it going it was state of equilibrium.
Once these two issues were corrected I still wasn’t really happy with how easily the siphon would start nor how quickly would run. I really didn’t have a feeling of confidence that the system would run unattended for a few days at a time. Being to be able to depend on the bell siphon running automatically without intervention for at least the width of the weekend, perhaps five days, is absolutely crucial to be able to leave the system alone without a fish kill.
It’s important to note that the water quality, upon which the fish depend, is completely dependent upon the filtration provided by the ebb and flow of the water through the gravel beds. If this cycle of ebb and flow is interrupted, then the quality of water degrades, the content of ammonia increases dramatically, and it will eventually kill the fish. This can happen in as little as 24 hours.
While watching a video on YouTube I saw fellow who used a pop bottle for the cap of his bell siphon; a clear plastic pop bottle. His motivation was that he wanted to see how the bell siphon worked and so by using transparent plastic he could look through both the standpipe, the gravel or media guard, and the siphon cap and watch the process.
While I was watching his video I realized the shape of the pop bottle near the top was rounded. This means that as the water rose up the siphon, it essentially was forced to increase in height rapidly as it reached top of the bottle. This had the effect of ram-starting the siphon process.
Out of curiosity, I replaced one of the siphon caps in the more troublesome of the two grow beds with a 571 mL pop bottle. All I actually did was cut off the bottom centimeter and a half and drop it in place of the original PVC pipe siphon cap.
I was surprised and pleased how much more effective this works since the bottle I am using is not really rounded, at the top but almost conical. It is dramatic in how fast the water rises inside that part of the bottle and therefore consistently overwhelms the mouth of the standpipe. The siphon always starts; it has been running for a week now without a single failure.