Compost Bins Review

We share our experience using different types of compost bins; bottomless daleks,  tumbler and custom built frames

These impressions are based on 12 years of experience and  56 completed bin cycles (at the time of writing). We mainly focus on operational considerations and quality of the compost:

Reviewed criteria are:

1. Ease of top up: How easy is it to keep adding waste material

2. Ease of stir/mix: How easy is it to stir and mix  waste material

3. Empty bin: How easy is it to empty a bin once compost matured

4. Decay rates: How slow/fast does it take to decompose 

5. Quality of compost. Whether a bin type impacts quality of compost

6. Moving the bin: How easy is it to move the bin from one place to another

7. Product durability:  Comment on usability so far and expected  lifespan

8. Cost of the bins: In the United Kingdom

Summary

Experience so far

1. Ease of top up: The dalek bins top door (hatch) opens easily and it is easy to fill up & top up buckets of waste material. The one metre height is about right for easy access; same for the wooden frames' large opening. The tumbler has a screwed top that needs cleaning/clearing so as not to jam. The  entrance is also on the small side, just short of the bucket size we used. Not too difficult though, just more cumbersome than the other two types

2. Ease of stir/mix:  For dalek & wooden frame bins, we use two tools to stir and mix compost: (1) a garden fork for the edges and (2) a Dolmen compost mixer/aerator for the middle part. Rotating the tumbler is a much better and easier option; albeit when full, it is not as easy to rotate as some adverts make out.

   1. We stir/mix all compost bins on a weekly basis where possible (exceptions include either frost or the compost temperature above 30℃)

3. Empty bin:  The easiest bin to unload is the wooden frame. We designed this frame with a sliding front gate specifically to make it easy to access and unload the lower part of the bin. The dalek bins are not too difficult to  sleeve out (remove vertically), given they are bottomless. Some work by nudging them gently side-ways and  vertically until they come off. The tumbler however is quite cumbersome to empty; the compost gets stuck with the lower part of the tumbler barrel, unless the whole tumbler is elevated. Emptying the last 10% of the barrel is quite fiddly.

4. Decay rates:  The decay rates (waste into compost decay rates) are obviously governed by a number of parameters (volume added, quality & size of waste, stirring frequency etc..). Here we compare the three types of bins on a like-for-like basis. The dalek and wood frame have similar decay rates; the wood frame has a larger volume but allows more cold air entering the bin whereas the dalek bins have lower volumes but are tight in keeping heat in. So the decay rates are comparable.

   1. For the tumbler bin, the decay rates are much lower despite the easy mix. I interpret this as not having direct access to  soil; so the worms and other microorganisms won’t work as fast as the other two types. So for the tumbler, I add sieved soil to the waste mix. Also when I am doing garden activities, I collect worms and put them in the tumbler to help.

   2. The 190L argument (as small volume) is not enough for me, given I have a dalek bin with 220L that has consistently delivered better decay rates (faster decomposition) than the tumbler in similar conditions.

5. Quality of compost: The tumbler takes longer for the waste to decompose but it delivers the best quality; compared to the other two types. My interpretation is in  the quality of mixing and rotation that allow the green/brown to mix well. We mix the other bins on a weekly basis and get really good quality compost; the tumbler’s is excellent.

6. Moving the bin:  The dalek bin is the  easiest to move around the garden. The (empty) tumbler needs two people to move it.

7. Product durability: After 10-12 years, the daleks are still looking solid; as expected, being made of strong (black) plastic. The same partly applies to the tumbler; with one important exception: The supporting frame on which the tumbler rotates is made of metal and after 8 years of usage, some rust is appearing on the metal frame. 

8. Cost:  The cost of the tumbler bin (D) is higher than dalek bins A,B and C put together. At the time of our purchases, one could acquire ~4x dalek 330L bins for the price of one tumbler bin. The bins A,B,C were acquired through a Leeds city council scheme (discounted price) to promote home composting. Today, a tumbler bin typically would cost 2x to 3x the price of a dalek bin (on a like for like volume). The custom built bin (E) cost was mainly the wood material, relevant safe paint and assembly bits. We built the two custom frames ourselves (hence the "moderate" cost rating). Ready made shop-bought wood frames tend to be more expensive than the dalek ones, on par with tumbler  (but aesthetically more appealing).