Getting more from WSFs starts with your water

Water-soluble fertilisers (WSFs) are widely used to deliver fast, targeted nutrition. Yet, when planning a nutrition programme, growers frequently neglect to consider the characteristics of their irrigation water. According to ICL Technical Area Sales Manager Jason Colin, when water and fertiliser are properly aligned, the results speak for themselves – more consistent crops, better nutrient uptake, reduced wastage/risk of leaching and fewer system headaches.

How water quality affects nutrient uptake

Every irrigation event brings more than just hydration. It delivers a mix of dissolved salts and minerals that directly influence EC and pH in the root zone. These two factors ultimately control how available nutrients are to the plant.

High bicarbonate levels, for example, can steadily push pH upwards. Over time, this can lead to nutrient lock-up, particularly with elements like iron and phosphorus.

Water source also plays a role. Hard water typically carries calcium and magnesium, while softer sources like rainwater or stored reservoir water can lack these key nutrients altogether. Then there’s the practical side, if the fertiliser and water chemistry aren’t compatible, you can end up with precipitation that blocks emitters and restricts flow.

This is why water analysis isn’t just a box-ticking exercise, it’s the foundation of any effective feeding strategy.

Choosing the right WSF for hard or soft water

ICL’s water-soluble ranges are built with these challenges in mind, enabling growers to match products directly to their water profile, rather than working against it.

The gold standard, Peters Professional and Peters Excel are ICL’s go-to ranges for high-value crops or situations where precision really matters. Their advanced chelation technology helps keep nutrients available, even when conditions aren’t ideal. Within the Peter Excel range, acidifying formulations are designed to counteract high bicarbonate levels in hard water, helping stabilise pH and maintain clean systems.

For nurseries using softer water, our dedicated Peters Excel CalMag options ensure plants receive the calcium and magnesium they might otherwise miss.

ICL’s versatile Universol range offers a reliable and great value alternative, with the added simplicity of a colour-coded system that makes mixing and application straightforward.

Like our Peters ranges, the Universol range includes specific formulations for both hard and soft water. Hard water options help manage bicarbonates and support pH stability, while soft water formulations focus on delivering a balanced nutrient profile that supports steady growth and strong root development.

In both cases, the goal is the same, work with your water, not against it.

How to get better results from Water Soluble Fertilisers

For growers looking to get the most from their nutrition programme, following these steps can make all the difference.

Start by testing your water regularly. Your local ICL Technical Area Sales Manager will happily take a sample and have it sent to an independent laboratory for analysis, before going through the results with you. Knowing your pH, EC and bicarbonate levels gives a clear baseline to work from.

From there, selecting the right fertiliser becomes much more straightforward, whether you’re adjusting for water type or aligning with a specific growth stage.

Our digital AngelaWeb 3.0 precision nutrition platform takes any guesswork out of the process. It enables the ICL team to build tailored nutrition programmes based on your exact water analysis, helping fine-tune inputs and improve overall efficiency.

Better water management delivers more consistent plants

When fertiliser choice is aligned with water quality, everything improves – nutrients remain available, crops develop more uniformly, and irrigation systems stay cleaner for longer. It’s a simple shift in approach, but one that can deliver measurable gains across the entire production cycle.

So, if you are unsure which of our WSF formulations best suit your crops and water conditions, contact your local ICL Technical Area Sales Manager.  Our FACTS qualified team is on hand to help ensure you get the best possible return from your feeding programme.