PondPoise
The Journal
How Big Should Your Goldfish Pond Be? A Volume & Sizing Guide
Volume is the number every other pond decision depends on. Here's how to think about size, depth, and shape before you dig, with a worked example.
Goldfish vs Koi: Which Pond Fish Is Right for You
Goldfish and koi look similar at a glance but differ enormously in size, space needs, and lifespan. Here's how to decide which one fits your pond.
How Many Fish Can Your Pond Actually Hold? Stocking Density Explained
The gallons-per-inch rule is the standard way to check stocking density. Here's what it means, where it comes from, and what can shift it.
Pond Filtration 101: Choosing the Right Pump and Turnover Rate
A pond filter's job is to keep up with your fish's waste. Here's how mechanical and biological filtration work, and how to size a pump correctly.
What and How Much to Feed Goldfish and Koi Through the Seasons
Goldfish and koi are cold-blooded, so feeding needs to track water temperature through the year, not a fixed daily routine. Here's how.
Water Changes 101: How Much, How Often, and Why It Matters
A running filter doesn't remove everything from pond water. Here's why partial water changes are still necessary, and how to size one correctly.
Choosing and Sizing a Pond Liner: A Beginner's Guide
A flexible liner is the most common way to build a garden pond. Here's how to choose a material, size the sheet correctly, and install it well.
Calculating True Pond Volume: Why Shape Can Mislead the Estimate
Two ponds with identical length, width, and depth can hold very different amounts of water depending on shape. Here's why, with side-by-side worked numbers.
How Much Overlap Does a Pond Liner Really Need?
The overlap allowance is the smallest number in the liner sizing formula, but it moves the total square footage more than people expect. Here's the math.
The Nitrogen Cycle: Why a New Pond Must Be Cycled Before You Add Fish
Ammonia and nitrite are acutely toxic even at low levels, and a brand-new filter can't handle either one yet. Here's the nitrogen cycle, and how to cycle a pond safely before stocking it.
How Much Filter Turnover Does Your Pond Actually Need?
Turnover rate depends on what's actually living in the pond, not just its volume. Here's how the target changes by fish type and stocking level, with numbers across several pond sizes.
Realistic Stocking: Goldfish vs Koi in the Same Size Pond
The same three fish can be comfortably stocked or badly overstocked depending only on pond size and species. Here's what that actually looks like with real numbers.