Why use potassium-based polymer instead of sodium polyacrylate?
Sodium released into soil can damage soil structure over time. Potassium-based polymers like AuraSorb 9000 are designed for use in the root zone.
Horticulture and Root-Zone Water Retention
Hold extra water in sandy soils and free-draining potting mixes and release it to roots between waterings.
AuraSorb 9000 Series water-retention polymers are potassium-based acrylate–acrylamide copolymers designed to work in soil. AuraChem helps nurseries, landscapers and growing-media producers choose particle size and placement for their mix and irrigation water.
Why Potassium-Based Polymer Is Used in Soil
Superabsorbents made for waste treatment and hygiene products are usually sodium polyacrylates. Repeatedly releasing sodium into soil can degrade soil structure, which is why polymers made for horticulture use potassium instead. AuraSorb 9000 is a potassium-based acrylate–acrylamide copolymer, built to swell, release water and swell again in the root zone.
The polymer suits media that drain fast and dry out quickly: sandy soils, bark-based potting mixes, hanging baskets, green roofs and new plantings that have not yet rooted into surrounding soil.
Sandy Soils, Hot Summers and Bore Water
Much of Australia's urban and peri-urban growing happens on sandy soils, from Perth's coastal plain to sandy loams in South Australia and Victoria, under long hot summers and water restrictions. Water applied to these soils drains past the root zone quickly, which is the gap a water-retention polymer is meant to fill.
Irrigation water quality matters. Bore water and recycled water can be saline, and fertiliser adds dissolved salts. Both reduce how much the polymer holds, so performance should be judged in the water actually used on site, not in rainwater.
How the Polymer Stores Water in the Root Zone
Mixed into soil or potting media, the dry granules absorb irrigation or rain water and swell into soft gel particles. As the surrounding medium dries, roots and soil draw water back out of the gel, and the particles shrink until the next watering rehydrates them.
The polymer evens out the swings between wet and dry. It does not create water or replace a sensible irrigation schedule. Over-applying it can make media swell and heave or lose air space, so rate and placement matter as much as the product itself.
Trialling Polymer in a Growing System
- 01Describe the system. Note the soil or mix, plant type, container or bed design and how it is watered.
- 02Test swelling in your irrigation water. Use the bore, mains or recycled water and fertiliser solution actually applied.
- 03Choose particle size. Fine grades mix evenly through potting media; coarser grades suit planting holes and beds.
- 04Set a trial rate. Check drainage, air space and any surface heave in the swollen mix.
- 05Run a side-by-side trial. Compare treated and untreated plants under the same watering before wider use.
Selecting AuraSorb 9000 for Your Mix
Relevant Product
When It May Be Selected
Application-Rate Approach
Relevant ProductAuraSorb 9000 Series
When It May Be SelectedPotassium-based acrylate–acrylamide copolymer for potting mixes, landscape beds, tree planting and turf establishment. Particle size is chosen to suit mixing into media or placing in planting holes.
Application-Rate ApproachRate is set in the actual growing medium and irrigation water, leaving room for the polymer to swell without heaving the mix.
Growing Conditions That Affect Performance
Variable
Why it matters
Soil or mix texture
Sandy soils and bark mixes benefit most; heavy clay benefits least
Irrigation water salinity
Bore, recycled and fertilised water reduce swelling
Placement depth
Polymer must sit in the active root zone
Particle size
Fine for even mixing; coarse for holes and beds
Application rate
Too much can heave media and reduce air space
Container, bed or field
Each has different swelling room and drainage
Benefits for Growers and Landscapers
These are potential operational benefits subject to material testing and field or production validation.
Extra water held in sandy soils and free-draining mixes
Smoother moisture between waterings for containers and baskets
Support for new plantings while roots establish
Rehydrates with each irrigation or rain event
What a Growing Media Trial Shows
A trial compares swelling in your irrigation water, checks drainage and air space in the treated mix, and gives a starting rate and particle size for a controlled planting trial. It does not guarantee water savings or yield, which depend on climate, plants and irrigation management.
Water-Retention Polymer FAQs
Does saline bore water reduce performance?
Yes. Dissolved salts limit swelling, so polymer holds less in saline bore or recycled water than in rainwater. Trials should use the actual irrigation water.
Can it be spread on top of the soil?
Granules on the surface dry out and can wash away. Mixing into the root-zone media or placing in the planting hole gives more reliable results.
Will it let me water less often?
It can lengthen the time between waterings in free-draining media, but irrigation still has to match the plants, climate and mix.
Related Water-Holding Polymer Applications
Superabsorbent Polymers for Gel Ice Packs
Uses a superabsorbent to hold water in a stable gel, in a sealed pack rather than in soil.
Relevant Products
Plan a Trial in Your Growing Media
Tell us about your mix, plants and irrigation water and we will suggest an AuraSorb 9000 particle size and trial approach.