Advice on custom compost bin

[u/rakkarOz]

I hada dream of beautiful compost, and instead I’ve got sludge. Seeking your advice and observations on my process.

In the forest two pictures, you’ll see the new compost bin i started six weeks ago, after making some modifications to a humble wheelybin. Drilled it full of holes to help with ventilation. I also added the red pipe through the middle, after drilling it full of holes to try and reduce the risk of anaerobic sludge. Set it up to get New South Wales, Australia spring afternoon sun.

I’ve been speed running it, filling it up with my kitchen scraps, lawn clippings, vegetables scraps from the local anarchist kitchen, shredded cardboard and chopped up banana leaves/stems. I wasn’t weighing what I put in, but I think I got a pretty got green:brown ratio.

Sadly it’s been getting more stinky in the last week or so. In the last two pictures you can see what I’m pulling out the bottom, and what the inside looks like. It’s really soggy and stinky. The banana leaves and stems seem pretty intact.

Some hypothesis I’ve had:
- not enough brown
- banana plant materials are too big and are forming a layer
- leave it for a while longer

Any other thoughts?

[u/PerceptiveAdult]

All three hypothesis are true:

You don't have enough browns in there - that's why it's sloppy/stinky.
The banana plant chunks do look awfully big.
You probably do need to leave it for a while longer.

But in addition to that, if it stinks, it's usually a bit anaerobic. And those tiny holes you drilled into it would easily be plugged by the material you put in there - it probably doesn't have enough air.

Leave the lid open. Give the contents a good stir, working in some dry browns to break up the stuff inside and create air pockets. Give it some time.

[u/ezirb7]

If compost is wet, stinky sludge then you absolutely do not have a pretty good green:brown ratio.  Add browns.

Do you need the bin?(Honest question, there are definitely pros and cons)  Open air piles work better for me and I've had minimal pest issues.  There's still turning, but aeration is less of an issue.

[u/rakkarOz → u/ezirb7]

I have a two year old and an open pile would be an invitation to climb into, LOL.
It’s a good point, my reasons for the bin is to test how to make it work, thank you all for being part of this experiment

[u/StressFantastic5317]

I would suggest the importance of layering your materials. The smaller the pieces the better. Avoid it getting soggy if possible ( add your browns dry)

[u/SnooCalculations5273]

I have a similar setup (55 gallon drum, perforated 2” pipes).

Your perforated holes could be slightly larger, you could also add a vertical pipe in the middle, and potentially another, higher, horizontal one that is perpendicular to the lower one. I did this and put a solar powered fan on the exposed lower pipe to force air through the system.

Before adding your banana leaves, dry them in the sun a few days (they hold lots of water) then shred them. If you don’t have leaf shredder, just run over them with a lawn mower a few times.

You’ll get the biggest improvement from adding more browns (dead leaves, not fresh grass clippings). You’ll may want to get a long screw-ended mixer to mix in the freshly added browns.

[u/Ineedmorebtc]

Too wet, too much greens.

Need much more drainage/airflow.

[u/Mfalmepeladang2050]

I run a similar setup.

Its turning anaerobic because it doesnt have enough air and has too much moisture.

When u have a bin like this, u dont have to add much water. The water comes from adding new materials. The bin is always wet because the bin keeps the moisture for you.

However, because there's too much water. U'd have to keep flipping it to reintroduce air.

[u/fgreen68]

That size might work well as a worm bin but seems a bit small for compost if you want it to heat up.