UPDATE!
well here's my mini system!
I decided to use a plastic trash bin as a reservoir/sump, and trash bag as a liner for easy cleaning, all I'd have to do is drain the sump and replace the liner with a new one. When I do expand with more grow beds, I simply add more trash bin sumps, more fishes and/or tanks. The main goal is to have many little grow beds, as opposed to one big grow bed, as it allows repositioning to catch direct sunlight as the sun moves throughout the day.
I learned a lot about the importance of a well built bell siphon. The first trial worked really well (beginner's luck again) but I didn't know why it worked until I cut the drain pipe and bell to set the planter's water level lower. After that cut, the bell siphon just wouldn't work! It turned out that the tip of the drain pipe needs to be cut cleanly cos rough edges will create turbulence and water will not pour down evenly over the edges and you won't get the suction you need to suck down air that's trapped inside the bell. Also, you'll need to cut the drain pipe straight, which is difficult to do with a hack saw. My cut ended up slightly angled but it worked out since the wooden garden hutch's lid/roof that the tank and planter sits on is also angled, as you can see on the water's level at the left side of the tank.
I decided to simplify the overflow prevention system by using the same mechanism as a toilet tank..in just a few hours I built this:
The float cost $7. I could've made one with a plastic bottle but I wanted it to look good, and not too bulky, and the ball form factor is best for maximum buoyancy. The valve is a lid off a 35mm film can, and the clamp was a bicycle light handlebar clamp. Works really well, I AM VERY PROUD. Eventually, I'll upgrade to a real toilet tank mechanism if I find a used one, a new one is about 40 bucks.. my inlaws have a plumbing biz, they might have a used one in their warehouse.
So what happens to the water trapped in the grow bed when tank's valve is shut?
View attachment 2On the next timer cycle the pump will flood in more water and it'll be drained by a plastic bottle operated drain plug, just like this badass guy's system
, and drain back into the sump, over and over until arduino alerts me with a failure report: tank pump error (er.. sum shit)
The tank will be filled with these wiggly little guys known in Japan as Doujou fish.
Don't know what they're called in English but they look like miniature catfish. They're inexpensive and in some cases FREE to children at town festivals. We had a bunch from last summer's town festivals but most of them died in the first few months, we're down to the last 3. This one in the photo is the alpha fish, eats all the fish food and the rest feed on his poop, :lol: he's the biggest and the ultimo hombre, last man standing.
OH BTW, I found my pepper plant sprouts infested with aphids, feeding off tiny young leaves sprouting between branches. I brushed them off with a fine tip brush and hammered those suckers. They look just like them robots in the Matrix films. The sprouts will be fine, I'm glad I caught them early!
more later, so stay chooned!