Pro PK - Phosphorus & Potassium Booster (1L + 5L + 20L)

What is Pro PK and how is it used?

Pro PK is a phosphorus and potassium bloom booster designed to support flower and fruit development during early to mid-flowering. It’s a supplement, not a base fertiliser, and is ideal for flowering ornamentals, fruiting veg, and heavy-yield plants. Use it alongside your regular nutrient program to meet increased PK demand during bloom.

When should I start using Pro PK and for how long?

Begin using Pro PK about a week before flowers form and continue for the first 3–4 weeks of flowering. It’s not intended for veg or late flower. Always adjust based on plant response and environmental factors.

How much Pro PK should I use per litre, and how often?

Mix 1–2 ml per litre of water. Start with 1 ml/L if your plants are sensitive, and increase only if they’re healthy and feeding well. Use as part of your normal feed schedule during the bloom window, monitoring EC and plant response.

Is Pro PK suitable for soil, coco, and hydro systems?

Yes—Pro PK is compatible with all common grow mediums including soil, coco coir, and hydroponics. Just keep an eye on EC levels and runoff, especially in coco and recirculating systems.

What does Pro PK actually do during flowering?

It supplies extra phosphorus and potassium to support bloom size, density, and yield potential. While it won’t work miracles alone, it helps your plant make the most of its flowering stage when combined with good light, genetics, and base nutrition.

Can Pro PK cause nutrient burn or imbalances?

Yes—overuse can cause tip burn, leaf curl, or nutrient lockout (especially calcium/magnesium). Stick to label rates, monitor EC, and adjust your base nutrients to avoid pushing plants too hard.

Can I use Pro PK with CalMag or other base nutrients?

Yes, but reduce your base nutrient strength slightly to maintain balanced EC. Always mix Pro PK and CalMag separately into water (never directly together), and watch for any cloudiness that might signal a reaction.

What’s the proper mixing order for Pro PK?

Always add Pro PK to water first, stir well, then add base nutrients and any other additives. Adjust pH last. Don’t mix concentrates directly, as this can cause minerals to drop out and reduce nutrient availability.

Does Pro PK change pH or EC levels?

It can shift both, depending on your water and nutrient mix. Always check pH and EC after mixing, especially when using PK boosters, to avoid unintentional imbalances or lockouts.

Can I use Pro PK in drip systems or reservoirs?

Yes—Pro PK can run in autopots and drip setups, but always ensure it’s fully dissolved and agitated. Don’t let reservoirs sit warm or stagnant for long periods, and flush lines regularly to prevent buildup.

Is Pro PK suitable for organic or living soil grows?

It’s a mineral booster, so it’s best suited to systems already using bottled nutrients. In living soil or microbe-heavy setups, use it sparingly—too much mineral salt can reduce microbial performance.

How should I store Pro PK and does it expire?

Store Pro PK sealed, cool, and out of direct sun. Shake well before use. Like most liquid nutrients, it has a long shelf life when stored properly, but discard it if it smells off or shows signs of separation that don’t remix.

Should I foliar spray Pro PK or apply it through roots?

Pro PK is intended for root feeding only. Avoid using it as a foliar spray—high mineral concentrations can spot or burn leaves. Apply via top-watering or through your irrigation system.

Do I need to change anything else when starting Pro PK?

Monitor total EC, ease off base nutrients slightly, and avoid overwatering. If your plant seems stressed, lower the dose to 1 ml/L or reduce frequency until it recovers. Pro PK works best in a well-managed environment.

What sizes is Pro PK available in, and are they the same formula?

Pro PK comes in 1L, 5L, and 20L bottles. The formula is the same across all sizes—only the volume changes. The 20L is ideal for larger gardens or frequent use.