our greenhouse is 20'x20' with a 12'x20' tank/pump room. We have stacked beds to maximize space. Two of the beds are 16'x3' our big bed is 42"in x19.5', and we are building two more 8'x3'. The top beds are media and the bottoms are float beds. The media beds have two 1" bell siphons (the two 16' ft. beds) the big bed has three 1" bell siphons, and the small beds (8'ft.) will have two 3/4" bells. The 16'ft. float beds have three 11/2" drains. the big bed has four 11/2" drains, and the two small beds well have two 11/2" drains. We also want to run some NFT in the greenhouse. We have two 275 gallon fish tanks and a 275 gallon sump tank with a 55 gallon swirl filter. We are using a Iwaki 1344 GPH as a drive pump and a 400 GPH sump pump on a float switch. Now that the technicals are out the way the fun of the whole build for me was watching my sons. Seeing them in a whole new light as men working hard bouncing ideas off each other, them taking a personal interest in this project. This was the most unexpected pleasure I got out of it all. To see them interact with each other no longer as children but as men do. Made it worth everything and even if this is a total loss I most certainly would do it again for that reason alone.
Nice build. Also watched your videos. Thanks for the share. I was wondering how you get the siphons to fire together. Also not having beds as large you I wonder why you need multiple siphons. From what I understand all you need to do is cycle your fish tanks at least one time per hour and a 1" siphon should be able to dump enough water to do that while the pump still runs. A timer on the pump could be used too. I'm also curious how your system keeps flowing if you loose power or did I hear you incorrectly?
Thanks Jeff, for the comments and the questions. we are using a method we developed to get the bells to fire exactly at the same time every time and break. this is what we call the "Bell Link" method using this method you can link as many bell siphons together as you want or need too if you go to Youtube and search our namesake you'll find some videos about this. we are going to post them here later but we did not want to make anybody feel like we are crowding them but if there is enough interest I'll post them up. you are right in that a single bell is enough to cycle the tanks but in a large bed especially when the length is much greater then width you get what we call "water stalling" because it is so long the bell drains faster then the water can move through the bed with the media in it so the bell tends to break before the bed is actually drained. second reason and this is just a plus it tends to clean your beds a little better also has to do with timing on flood control of bottom beds. a timer on a single pump will not do what we needed in a system this large with different size beds each bed has a different fill rate. to minimize water level swing in our tanks we are displacing the extra water moving it from one point to another before overflow it is a tight rope act. the system can handle any three beds hitting at the same time but it uses the sump, FT, and the other beds being filled to do this so the pump must be on at all times. and yes you heard my correctly the system once started will siphon this was unattended an actually we at first thought we had a leak a big one till we discovered that it was siphoning to the grow beds. we have noticed quite a few unattended scenarios usually these are things you have to correct but we been blessed so far the majority of them have been in our favor so we leave will enough alone.
I have a small aquarium system in my basement with a 48"x10" GB for seedlings. It's only about 4" deep but I do experience the slow water flow from one end of the bed to the siphon. It actually overflows at one end if the water is flowing too fast. I gave up on the siphon and just do a constant flow.
Neat! Aquaponics was definitely a coming-of-age project for me as well.