Posted on July 10th, 2025

Algae growth is one of the most frequent challenges pond owners face, and it’s rarely caused by a single factor. Understanding the underlying reasons can save you time, money, and frustration while keeping your pond healthy and clear. From filtration issues and overcrowded fish to maintenance habits and environmental factors, there are several key contributors that promote algae blooms in ponds throughout Hampden County, Western Massachusetts, Northern Connecticut, and surrounding areas. Below, we break down the most common causes so you can identify potential issues and take steps to maintain a balanced, thriving pond ecosystem.

1. Improper/Not Enough Filtration

Contrary to popular belief, a pump sitting at the bottom of your pond is not an actual working filter. Most pieced-together ponds have a mix match of products in hopes of proper filtration. There are many systems that work really well, but they all take a pre-set amount of routine maintenance.

2. Too Many Fish or Over Feeding

Ponds that are overstocked with too many fish certainly promote pond algae. It is so tempting to buy and buy, forgetting that the koi we buy are babies. As they grow we have an even more acute lack of space and process ever-growing waste. Imagine a 4-inch baby has grown to 1 foot, 3 times in a few months! The end result is increasing nitrogen levels, which in turn become nutrients for algae blooms.

3. Lack Of Routine Maintenance

Unfortunately with pond filtration systems that look like this, regular back-washing and refilling expelled water can put a strain on your free time, and make it easy to neglect, causing a backup of alternate issues that compound themselves in multiple. You see green water, we see crashed ecosystems.

4. Non Regimented Water Treatment Applications

The improper usage, or complete lack of natural water treatments, promotes pond algae. A pond is only as healthy as the water in it. Treating pond algae with pond chemicals is not a long-term solution to this pond problem. It’s a quick fix that puts additional stress and loads on your pond. So take care and read all directions, before just dumping it into your Hampden County, Western Mass, Northern CT area pond.

5. Improper Pond Circulation

Poor pond circulation occurs usually when encountered with the cost of replacing a burnt-out pond pump. Most often people opt for a smaller pump to save money, but ultimately cause major circulation issues, which then they battle with endless additives and mixtures, trying to solve a problem caused by less circulation.

6. Excess Rainwater Nitrogen

We have noticed over the years that we receive many phone calls about algae blooms after long heavy rainy periods. The rainwater is full of nitrogen which is ultimately a fertilizer that algae can feed on. Having poor filtration, or low circulation, will enhance the algae blooms, based on how much rain the pond has collected.