---
product_id: 2284042
title: "Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735)"
brand: "tetra"
price: "€ 25.06"
currency: EUR
in_stock: true
reviews_count: 9
category: "Tetra"
url: https://www.desertcart.sk/products/2284042-tetra-pond-block-4-count-controls-algae-growth-in-ornamental
store_origin: SK
region: Slovakia
---

# Dissolves over ~30 days Treats up to 250 gallons each 4 blocks per pack Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735)

**Brand:** tetra
**Price:** € 25.06
**Availability:** ✅ In Stock

## Summary

> 🌿 Clear Water, Clear Mind — Own Your Oasis

## Quick Answers

- **What is this?** Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735) by tetra
- **How much does it cost?** € 25.06 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sk](https://www.desertcart.sk/products/2284042-tetra-pond-block-4-count-controls-algae-growth-in-ornamental)

## Best For

- tetra enthusiasts

## Why This Product

- Trusted tetra brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Long-Lasting Treatment:** Each block works continuously for about a month, ensuring steady algae management.
- • **Effortless Algae Control:** Keep your ornamental pond crystal clear without daily hassle.
- • **Safe for Fish, Not Plants:** Formulated specifically for ornamental fish ponds—avoid use with live plants for best results.
- • **Perfect for Medium-Sized Ponds:** One block treats up to 250 gallons, ideal for most home water gardens.
- • **Subscription-Ready Convenience:** Join the growing community of pond enthusiasts who never run out of clarity with easy reorders.

## Overview

Tetra Pond Block is a trusted, easy-to-use algae control solution designed for ornamental fish ponds. Each block treats up to 250 gallons and dissolves over approximately 30 days, providing long-lasting clarity. Ideal for containerized ponds without live plants, this 4-count pack helps maintain a pristine aquatic environment, enhancing the beauty and health of your pond.

## Description

For 50 year, fishkeeping enthusiasts have looked to the Tetra name for products and solutions that add ease and beauty to their home. Whether you're an experienced hobbyist or just starting out, Tetra has everything you need–from a large variety of quality fish food and innovative equipment to test kits and decor. Algae growth can quickly take over a pond and cloud your water. Conquer algae growth with TetraPond products so you can keep a beautiful oasis. TetraPond Pond Block removes pond algae for clean and clear pond water. Pond Block helps control algae growth in ornamental fish ponds. Use one block for water volumes between 100 and 250 gallons. Replace block when the previous block has fully dissolved for regular maintenance. Dissolving usually takes about 30 days. This pack contains 4 blocks. TetraPond Pond Block is for containerized ponds and fountains only. Not recommended for use with live plants.

Review: Works Extremely Well. More Than Satisfied. Great Price - Worked Extremely Well. Used 2 of the 4 blocks to start. Took about 10 day to really see any results and then added the other 2 blocks and water seem to get clearer as time went by. Still had some algae lingering but I don't have a very big filter. Can actually see my fish now....and some of the bottom. Signed up for a monthly subscription. Again EXTREMELY SATISFIED with this product. VERY REASONABLY PRICE and EASY TO USE.
Review: Controls Algae Growth Ornamental - Works good keeps my pond clear.

## Features

- Helps control algae growth in ornamental fish ponds
- Not recommended for use in ponds with live plants
- Each block treats 250 gallons
- Carefully follow dosage instructions
- Not for use in non-ornamental ponds

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0034CAYDO |
| Assembly required | No |
| Batteries required | No |
| Best Sellers Rank | #44,130 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #105 in Water Garden & Pond Treatment |
| Customer Reviews | 4.4 4.4 out of 5 stars (1,167) |
| Department | Unisex-Adult |
| Import | Made in the USA |
| Included Components | 1 x Controls Algae Growth In Ornamental Fish Ponds |
| Is Discontinued By Manufacturer | No |
| Item Weight | 5.6 ounces |
| Item model number | 16735 |
| Manufacturer | TetraPond |
| Product Dimensions | 3.75 x 2.25 x 5.5 inches |
| Specific instructions for use | Active |
| Warranty Description | See label |

## Product Details

- **Brand:** Tetra
- **Item Form:** Liquid
- **Item Weight:** 5.6 ounces
- **Liquid Volume:** 100 Gallons
- **Manufacturer:** TetraPond

## Images

![Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735) - Image 1](https://m.media-amazon.com/images/I/7183XbaKpgL.jpg)
![Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735) - Image 2](https://m.media-amazon.com/images/I/91r7NoLsaML.jpg)
![Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735) - Image 3](https://m.media-amazon.com/images/I/71-y7dKLBNL.jpg)
![Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735) - Image 4](https://m.media-amazon.com/images/I/51JgpeEAy8L.jpg)
![Tetra Pond Block 4 Count, Controls Algae Growth In Ornamental Fish Ponds (16735) - Image 5](https://m.media-amazon.com/images/I/91SHLv93I9L.jpg)

## Available Options

This product comes in different **Item Package Quantity** options.

## Questions & Answers

**Q: What are the ingredients?**
A: ACTIVE INGREDIENTS: Copper Sulfate pentahydrate 1.02%; 1-dimethylurea 0.51%OTHER INGREDIENTS: 98.47% NOTE: Ingredients taken from package label.

**Q: How long until you start to see the water clear up?**
A: The length of time it takes to clear up the algae will depend on a number of things such as the overall water quality of the pond, the stocking level, your filtration, the amount of organic matter in the pond, and so forth.  The more organic matter, the softer the water, the less effective and more time it will take.  In a situation such as this, we recommend a partial water change initially, prior to dropping the blocks in.  For more assistance, please contact the Tetra Consumer Relations Team at 1-800-526-0650.

**Q: Is the block supposed to disolve? its been in my pond for two weeks and still the same as when it went in.**
A: No. That's why I like it. It gets smaller over time and takes about 3 - 4 weeks to disappear.

**Q: will the Tetra Pond Anti Algae Block work in a 40 gallon aquarium that has 2 turtles
that are 30 years old.  Will it harm them.**
A: I use it in my goldfish pond. And my box turtles have access to it. No harm has come to either animal as long as the water is aerated.  This product removes the oxygen from the water.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works Extremely Well. More Than Satisfied. Great Price
*by K***N on October 7, 2025*

Worked Extremely Well. Used 2 of the 4 blocks to start. Took about 10 day to really see any results and then added the other 2 blocks and water seem to get clearer as time went by. Still had some algae lingering but I don't have a very big filter. Can actually see my fish now....and some of the bottom. Signed up for a monthly subscription. Again EXTREMELY SATISFIED with this product. VERY REASONABLY PRICE and EASY TO USE.

### ⭐⭐⭐⭐⭐ Controls Algae Growth Ornamental
*by L***A on January 4, 2026*

Works good keeps my pond clear.

### ⭐⭐⭐⭐⭐ I decided to try these algae control blocks and am glad I did
*by M***H on June 13, 2016*

Update 6/15/16- I have already purchased my second package of these, I am that happy with the results. I had to use a few to get it going, and then I think my turtles ate one! Seriously, it was only half dissolved this morning and now it is gone. They are acting fine, added a new one up on the waterfall so they can't get at it this time. I will never be without these again. Will look into getting the big tub of them next time. My pond was a big green mess. I previously tried barley bales and liquids which did nothing at all. I decided to try these algae control blocks and am glad I did. I just received these 2 days ago, and already I can see my fish, turtles and the bottom of my pond again. Still has a ways to go to be totally clear, but I am amazed. I dropped 2 of these tablets in along with one of their sludge reducer blocks. My pond is not large, it is a preformed plastic one we bought at Home Depot, I think 250-300 gallons. Nothing I have ever tried has worked, summer is the worst, full of algae all season long. As well as being able to see to the bottom and my animals again, the walls of the pond are clear from the thick algae that was growing. I don't have any plants in my pond, as the turtles eat them the instant I put anything in, so I can't speak to the safety of plants but the turtles, goldfish and mosquito fish are all a-ok.I know, it doesn't look great, but if you had seen it before... Fish and turtles were not visible 2 days ago. I will post another picture/time frame once it is clear. Second picture you can see the bottom of my pond. Still needs to clear up a bit, but after 3 days the bottom of my pond is visible again!

## Frequently Bought Together

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*Product available on Desertcart Slovakia*
*Store origin: SK*
*Last updated: 2026-03-20*