Fixing pH 3.3 soil with a KOH rain-barrel mix

I woke up this morning with way too much to do and way too many things in my head. But first I needed to deal with the most urgent situation: the pH of the lower soil/compost in my raised bed was down to 3.3.

Yesterday I tried to raise the pH by adding hardwood ash from my fireplace. After that attempt, I decided I needed to take more drastic measures.

A white 5-pound tub of DIYchemicals potassium hydroxide (KOH) with poison and corrosive warning labels, sitting on a brown tabletop — 5 pounds of potassium hydroxide (KOH)

The rain barrel

An orange rain barrel sitting under a downspout at the corner of a tan shed, with a wood fence and a shelf of supplies behind it — The rain barrel under the shed's downspout

Looking down into the open top of the orange rain barrel, with dark water close to the rim — Almost full

I came out and saw the rain barrel, and to my surprise it was almost full.

A small teal bilge pump lying on the lawn with black tubing and a thin wire coming out of it — The bilge pump

This is the bilge pump I'm using to mix the solution and to water the compost pile and my raised bed, which is composting too.

A line running across the lawn from the rain barrel by the shed to the corner of the raised bed's wood frame — The line reaches all the way to the bed

The line reaches all the way into my raised bed.

Black hoses looped over the rim and back into the orange rain barrel beside the shed — The line back in the barrel to circulate

I put the line back into the barrel so the pump circulates the solution.

The opened tub of potassium hydroxide, full of white flakes, sitting on the grass beside the rain barrel with its lid off — What the KOH looks like

This is what the KOH looks like. I added about 1/5 of a 12 oz water bottle full of the flakes to the barrel.

A hose sprayer pouring water into the open rain barrel, with black lines draped over the rim — Adding high-alkalinity well water

I also added some of my well water, which is high in alkalinity.

A one-gallon jug of Duda Energy food-grade phosphoric acid, 85% purity, wrapped in a clear plastic bag, held over the rain barrel — Food-grade phosphoric acid, 85%

To help buffer it at first, I used 85% phosphoric acid.

A hand holding a 20 mL syringe with about 5 mL of clear phosphoric acid over the foamy water in the rain barrel — 5 mL of phosphoric acid

I used 5 mL of it to balance and buffer the pH to 10.

A hand holding a pen-style pH meter in the brownish, foamy water of the rain barrel; the display reads 10.03 — The pH of the finished solution: 10.03

Watering

A hand holding the end of a black line with water running out onto dark compost dusted with gray ash, inside white tarp walls — Watering the compost pile

I watered the raised bed first, then the compost pile.

Close-up of compost with dozens of thin green milo sprouts and swollen seeds among dead leaves and bits of charcoal — Milo sprouts

The sprouts are milo seeds. I had meant to compost them, but I added them to see whether they would survive the pH 10 water.

A hand holding a 20 mL syringe of phosphoric acid over the rain barrel, now much lower, with black lines running down inside it — 15 mL more acid for the rest of the barrel

After that I added 15 mL more phosphoric acid to balance the pH of what was left in the barrel, so I can use it later for fertilization water.

Cabinet doors for the raised bed

The raised bed with a new wood frame built on top: open rectangular door frames along the side, a clear cover on top, and blue lines running across the soil inside — The door frames on the bed

I just made the cabinet doors for the raised bed. This shows what the frames look like and what the bed is going to look like.

Two rectangular wood door frames and a loose board leaning against boxes on a concrete patio next to the shed — The doors I've made so far

These are the cabinet doors I've made so far. One of them wasn't made with the right size wood, so I only have 3 good ones. I have to make another one today.

A pile of precut 2x2 boards on a workbench in the garage, with more boards leaning against the front of the bench — Precut wood for the rest of the frames

I've precut all the wood to make the cabinet frames for the raised bed.

Close-up of a board with a large knot that has a gap and a broken-out section — A gap to fill with wood putty

There are gaps I have to fill with wood putty later.

Electricity all around the bed

A coil of metal-clad electrical cable sitting on the edge of the raised bed next to a tape measure, with an outlet box mounted on the post behind it — 120V 14/2 wire

This is the 120V 14/2 wire I'm going to have to run around the bed, so I have access to 110V electricity all around the bed.

A power setup mounted on the wood side of the raised bed: a black scooter battery on top, a finned silver buck converter, a small buck converter, terminal rails, and a black case covering the 12V panel, all connected with red, black, yellow and blue wires — My 5V and 12V rail power setup

This is my 5V and 12V rail power setup. It starts with the scooter battery on top. The silver buck takes the 36V from the battery and brings it down to 12V. The 12V then goes to the 12V panel/rail, which is covered by the bed probe computer case.

The smaller buck below the battery, to the right, takes 12V down to 5V. The two rails next to it are + and − for the 5V.

The radiator

A small black 12V water pump labeled AW500S, Hmax 4–6 m, Qmax 600–800 L/H, lying on a black surface — The AW500S 12V pump

This is the pump I'm going to use to circulate water into my raised bed through the radiator.

A large gray wheeled trash can with a small device and cables on its lid, a shovel leaning against it, next to a white tarp — The reservoir for the radiator water

This is the reservoir I'm going to use for the radiator water.

A tall roll of double reflective bubble insulation, 1.21 m by 7.62 m, standing on the patio next to a chair — Insulation for the reservoir

This is the insulation I'm going to use around the reservoir.

Several square Peltier modules with red and black leads lined up on a windowsill — The Peltier heater setup

This is the Peltier heater setup I plan to use to heat the radiator. That's another thing I need to do.

The MCU box

A small black 3D-printed box on a printer bed; the printer's screen says Printing Completed, 1h2m, 21g — Just off the printer: 1h 2m, 21 g

This is the 3D-printed MCU box I just made, right as it came off the printer.

A hand trying to fit a USB cable's plug into a hole in the side of the small black printed box — The hole was too small for the USB cable

It wasn't sized properly: the hole was too small for the USB power cable to fit into. So I made the hole bigger.

A laptop running Bambu Studio with three of the MCU boxes arranged on the build plate — Three MCU boxes ready to print in Bambu Studio

Then I decided to print three of them in Bambu Studio.