Supa Anti-Algae Pond Block
When placed into the pond, this block slowly dissolves, releasing di-methyl urea into the pond water. Whilst totally harmless to fish and healthy pond plants, it inhibits the growth of water-born algae. Prevention is always better than cure, so introducing this item in early spring will help prevent algae build-up as the weather warms.
Product Specifications
| Feature | Detail |
|---|---|
| Active Ingredient | Di-methyl urea |
| Form | Slow-dissolving block |
| Usage | Place directly into pond water |
| Effect | Prevents algae growth |
| Safe For | Fish and healthy pond plants |
FAQ
How long does it take for the anti-algae block to start working?
The block begins to dissolve gradually and starts releasing di-methyl urea within a few days of placement. Full effectiveness is typically seen within one to two weeks after introduction.
Can I use this block in a pond with fish and aquatic plants?
Yes, the product is safe for fish and healthy pond plants. It does not harm aquatic life or interfere with plant growth.
How often should I replace the anti-algae block?
Replace the block every 4 to 6 weeks depending on pond size and algae activity. Monitor water conditions and replace when the block is significantly degraded or no longer dissolving.

Carolyn Hemmings –
I’ve used this block for three months now and have noticed a significant reduction in algae growth. My fish and plants are thriving, and I no longer have to clean the pond as frequently. Easy to install and effective.
Kimberly Ogden –
It works well in my small koi pond. The block dissolves slowly and doesn’t affect the water quality. I’ve seen fewer green patches since I started using it in early spring.
Penelope Newman –
Great product for preventing algae. My pond stays clear without any harmful chemicals. The block is durable and lasts longer than expected. Highly recommend for pond owners.