Water Plant Fertilizer

In high light or summer, add 1 tsp per 10 gallons of water once a week; in low light or winter, cut back to once monthly. You can also measure it as 1 oz per 60 gallons or 3/4 tsp per cubic foot of water. Add it in a high-flow area of the pond so it disperses evenly. Because you're dosing the whole body of water, knowing your pond's volume in gallons is the key to getting the rate right.

At 1 tsp per quart, the 8 oz bottle makes about 48 watering cans of feed. For a typical shelf of 10–15 plants fed every 1–2 weeks in season, that's several months of feeding — and the 32 oz bottle four times that.

It can if you overdo it — algae feed on the same nutrients your plants do, especially nitrogen and phosphorus, so over-fertilizing a pond is the most common cause of green water. This blend is deliberately low in nitrogen and phosphate to reduce that risk, but you still need to stick to the labeled rate and not exceed it. Healthy, well-fed plants actually compete with algae for nutrients, so feeding correctly helps keep water clear, while overfeeding does the opposite.

For a rectangular pond, multiply length by width by average depth in feet, then multiply by 7.5 to get gallons. For round or irregular ponds, estimate the average dimensions the same way. Container water gardens are easier — a common half-barrel holds around 25-40 gallons. Getting a rough volume matters here because the dose is per 10 gallons of water, so an estimate keeps you from over- or under-feeding.

This is a plant fertilizer formulated for aquatic plants, not a fish product, so follow the labeled rate carefully and don't exceed it — sudden nutrient spikes stress a pond ecosystem. Adding it in a high-flow area helps it disperse rather than concentrating in one spot. If you keep fish, introduce it gradually and watch the water; a well-planted, properly fed pond generally makes a more stable environment, but moderation is the rule with any pond additive.

During the warm, high-light season, pond plants respond over a few weeks with greener pads and stronger flowering on new growth. Water lilies in particular show better bloom and leaf color as they take up iron and potassium. Results are slower in cool or low-light conditions, when aquatic plants grow little and need only monthly feeding. Existing yellowed pads won't re-green, so you're feeding the new growth that follows.