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BioBizz Light Mix vs All Mix

Updated: October 2026

You have two BioBizz bags in the basket because both titles say organic potting compost, and you need to know which one will scorch a seedling. BioBizz Light Mix vs All Mix is a feed decision, not a size decision. Light Mix is the lightly fertilised bag for seed, cuttings, and anyone who will feed early. All Mix is the heavily pre-fertilised bag for a plant that can take a rich start, after you moisten it and wait. Neither amazon.co.uk row in this set prints peat-free. The other brands stay on the [bio compost comparison](/hub/fertiliser-soil-and-bark-mulch/bio-compost). Products Compared used the stored listings and BioBizz's own pages.

You have two BioBizz bags in the basket because both titles say organic potting compost, and you need to know which one will scorch a seedling. BioBizz Light Mix vs All Mix is a feed decision, not a size decision.

Our top picks

BioBizz BioBizz Light Mix 20 L

Best overall

BioBizz BioBizz Light Mix 20 L
9.4/10about £10.44
View offer
BioBizz BioBizz Light Mix 50 L

Rank 2

BioBizz BioBizz Light Mix 50 L
10.0/10about £17.15
View offer
BioBizz BioBizz All Mix 20 L

Alternative

BioBizz BioBizz All Mix 20 L
8.6/10about £10.70
View offer
On this page
  1. 1.What each mix is for
  2. 2.What the amazon.co.uk rows show
  3. 3.Peat and organic words
  4. 4.When to pick which

What each mix is for

BioBizz describes Light Mix as lightly fertilised, and you add liquid feed from early on. All Mix is the other recipe. BioBizz calls it heavily pre-fertilised for about a couple of weeks, and says to moisten it and leave it 36 hours. One reviewer said tomato starters died because the mix was too rich. A 50 litre Light Mix is still Light Mix. Once you have chosen, watering is on how to use peat-free compost.

What the amazon.co.uk rows show

Light Mix 50 litres is £17.15, listed at 12 kg, with 4.5 from 234 reviews. Light Mix 20 litres is £10.44, listed at 5 kg, with 4.6 from 122 reviews. All Mix 20 litres is £10.70, listed at 5 kg, with 4.4 from 146 reviews. The 20 litre bags are close in cash. The 20 litre Light Mix title also prints 50 L and 10 L. One reviewer received 20 litres after expecting 50. The weight line is the check: 5 kg against 12 kg.
BioBizz BioBizz Light Mix 20 L

Testsieger

BioBizz BioBizz Light Mix 20 L
9.4/10about £10.44
View offer

Peat and organic words

The amazon saved listings do not say whether these bags contain peat, and they do not name the Soil Association. Silence is not a peat-free claim. BioBizz's blend article says All Mix contains peat-based components. That is the maker's line, not a lab report on the parcel, and it is enough to stop a peat-free label on All Mix. Hyjo lists peat moss and sphagnum peat in Light Mix. Hydro Harvest mentions OMRI and SKAL. Those names are not on these amazon listings, and they are not a Soil Association mark. More on the law is on peat and organic labels.

When to pick which

Choose Light Mix for sowing, cuttings, or a feed you run yourself. Take 50 litres at £17.15 if you can carry 12 kg. Take 20 litres at £10.44 only after the variant says 20 litres. Choose All Mix when the plant is already growing, and moisten it for 36 hours first. Neither listing states peat-free or shows a Soil Association symbol. Westland and DIVCHI are on best organic compost.

Common questions

Which one for seed and cuttings?
Light Mix. BioBizz aims it at seedlings, young plants, and cuttings, and expects you to feed from early on. In this set that is either 50 litres at £17.15 or 20 litres at £10.44. All Mix is the bag a reviewer found too rich for tomato starters. Sowing into All Mix because it was the BioBizz you could carry is the swap this page is here to stop.
Which one for a plant that is already growing?
All Mix, if you want the compost to carry about a couple of weeks of feed, after a 36-hour wait. Light Mix still suits a growing plant when you would rather add liquid feed yourself and avoid a hot start. The amazon All Mix row is only 20 litres, so a large pot may need more than one bag. A 50 litre All Mix is not in this comparison.
Does All Mix need a wait before planting?
Yes, on the maker's page. BioBizz says to moisten All Mix and leave it 36 hours before planting, then let it dry between waterings. The amazon bullets say strong pre-fertilised and do not repeat the 36 hours. Follow the maker if you are using this recipe. Light Mix has no equivalent wait in the saved listing.
Is either mix peat-free?
Not on these sources. The amazon listings do not say peat-free. BioBizz's blend article says All Mix contains peat-based components. Hyjo lists peat moss and sphagnum peat in Light Mix. That is a shop composition, not a test of your parcel, and it blocks a peat-free claim. Organic in the title is not a peat-free claim and not a Soil Association mark.
Why do the amazon titles list 10 L, 20 L, and 50 L together?
The 20 litre Light Mix title prints all three sizes, while the variant and the 5 kg weight are the 20 litre bag. One reviewer expected 50 litres and received 20. The 50 litre Light Mix is a separate listing at 12 kg and £17.15. Read the variant you have selected. The words in the title are how the wrong sack ends up at the door.
Will Light Mix burn seedlings the way a rich multipurpose can?
It is sold as the lighter of the two, and the burn review in this set sits on All Mix, not on Light Mix. That is not a promise that every Light Mix bag is gentle. The listing has no EC figure. Sticks, a very dry bag, and mould are the Light Mix complaints actually written out. If you want a hotter start, you are describing All Mix, and you should not use it for the first sowing.
Can I compare the 20 L All Mix with the 50 L Light Mix on price per litre?
Yes, and the 50 litre Light Mix is cheaper per litre, at about 34p against about 54p. You would be comparing a light 50 litre sack at £17.15 with a rich 20 litre sack at £10.70. The bigger bag costs more at the till and feeds less hard. Use price per litre after you have chosen the recipe, not instead of it.

Related pages

Bio compost comparison

Best organic compost UK

How to use peat-free compost

Peat and organic labels

Organic compost buying guide: size, feed and labels

Sources

Public UK and maker sources from the research digest, used for this page in October 2026. Prices, stars and review counts are the amazon.co.uk figures stored for these five listings. Organic wording is not a certifier. All Mix's peat line is the maker's blend article, not a test of the bag in your hand. No ban on amateur peat sales is in legislation.

  1. Defra, horticultural peat announcement, 27 August 2022 (retrieved 19 October 2026)
  2. RHS, peat-free choices (retrieved 19 October 2026)
  3. Peat Free Partnership, legislation timeline (retrieved 19 October 2026)
  4. Environment Agency, compost resource framework (retrieved 19 October 2026)
  5. Soil Association, approved and verified inputs (retrieved 19 October 2026)
  6. Garden Organic, garden compost or potting compost (retrieved 19 October 2026)
  7. BioBizz, behind the blend (retrieved 19 October 2026)
  8. Which?, fungus gnats (retrieved 19 October 2026)