It’s no joke: at the time of writing this, lots of pond owners are already laying the foundations for a big algae problem in spring/summer! The increasing hours of sunshine cause algae problems to burst into action. However, the cause is ALWAYS an excess of nutrients and NEVER just the light. A bottle of distilled and thus nutrient-free water in the blazing sun is good proof of this. Without nutrients, algae can never grow - even in the strongest light.
The algae and plants that die in autumn/winter release the nutrients bound in them into the pond water, and nitrates (NO3) and phosphates (PO4) are formed. A water test for the two algae nutrients immediately shows how high the water load is. In summer, when algae growth is strong, the nutrients are of course hardly detectable, as they are bound INSIDE the algae. Only when the algae die (even after using an anti-algae agent!) do the nitrate and phosphate levels increase drastically. With the low light incidence in winter, they do not lead to algae problems. But when the amount of light increases in spring, the table is richly set for the next generation of algae! If you bind off nutrients now, you deprive the algae of their nutritional basis and prevent them effectively! JBL happens to offer two highly effective nutrient binders, JBL PhosEX Pond Filter and JBL PhosEX Pond Direct , for pond owners with and without filters respectively. If there is any need...