​It’s absolutely heart-breaking to wake up in the morning and find your fish floating in the pond – especially when you don’t know why it happened. If they don’t have any visible wounds on them, and it’s mid-Summer in Phoenix, the cause is probably suffocation.

Several factors can contribute to this issue:

• The build-up of mulm on the floor, creating a toxic environment of methane being released into the pond
• Too many fish in the pond competing for the available oxygen
• An over-abundance of plant life

​If any (or all) of these factors combine with the already low oxygen levels in warm water, the pond fish can suffocate. Here in Phoenix, during the summer, our nighttime lows can remain above 90 degrees! This sets up a very oxygen poor environment in our water to start with.  Warmer water naturally holds much less oxygen than colder water.

​An over-abundance of plant life provides plenty of oxygen in the daytime, but exhales carbon dioxide at night (photosynthesis). That’s right: too many plants allowed to grow out of control actually rob your pond of oxygen at night. Now, that’s not so bad in the wintertime, when cold water is oxygen-rich and the fish’s metabolism has slowed to a dormant rate, so they’re not in need of as much. But in the summer, the fish are more active, their metabolism is at full-throttle, and they need all the oxygen they can get.

Plants grow like wildfire in Phoenix from Spring through Fall, taking up the nutrients from the fish waste and adding shade and oxygen to the water all day long. Then nighttime comes along, and the plants reverse this process, stealing oxygen from the pond and releasing carbon dioxide, just like a human inhaling and exhaling. If you have a lot of fish (measured in inches) competing for that oxygen, someone’s going to lose -- and the plants can hold their breath longer than the fish.

Sun exposure, aeration, depth, plant varieties, etc. play a role in healthy pond-keeping practices. The following preventative measures are rules of thumb, and you need to remember that each pond is an individual and unique unto itself.

The first rule of ponding is to not over-fish your pond. Yep, there are a lot of really cool fish out there, and people are tempted to collect them all. If you want to do that, build a bigger pond with appropriate filtration for that goal. Otherwise, choose wisely. 

Experts agree that you should keep your fish collecting to between ½” and 1” of fish per ten gallons of water. And if you have other aquatic life in the pond, such as a turtle, you need to take that into account, as well. 

A well-maintained ecosystem pond really should only need a complete drain & clean every 3-5 years here in Phoenix. Preventative measures can extend that timeframe, or even eliminate it. That estimation changes depending on how many fish you have, other aquatic life in the pond, and how much food and waste accumulate. 

​The toxicity of the mulm building up on the floor of a pond depends on many factors: the types and size of your fish, the circulation system on the pond, the filtration system on the pond, etc. Preventative measures like netting the floor or adding sludge digesters to the pond regularly could actually keep you from ever having to worry about this issue.

​If your pond wasn’t originally planned for abundant fish-keeping goals, you should err on the side of caution when adding fish and stick to the ½” of fish per 10 gallons of water recommendation. 

If you’re just starting to think about a pond, you need to make sure you (or the professional you’re hiring) are clear on your goals of desired fish-keeping so that the design of the filtration system is appropriate.
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This is a big part of maintaining an ecosystem pond. In the wintertime, it’s no big deal because the water is cold and both the fish and plants are fairly dormant. Plus, a bit of extra dormant plant material in the pond makes for great cover for over-wintering amphibious life.  

But once Spring hits, those plants start growing like crazy! Just trimming off the dead leaves isn’t enough. You need to make sure you’re keeping the roots under control – which also has the added bonus of preventing water displacement leaks. A good rule of thumb is to keep your plants from covering over 50% of the pond’s surface area. If you have stellar aeration, you can have more; less aeration, less coverage. Sun exposure and depth play a role, as well.

Ponds need regular maintenance. Most well-built ecosystem ponds with appropriate filtration for their size need as little as 10 minutes a week, and provide hours of enjoyment. But it has to be done.

If you are unable, unwilling, or just plain too busy to do the maintenance, but still want a gorgeous living water feature, The Pond Gnome has maintenance programs for folks who want to do a little, a little more, or not a bloody thing!

​How can we help?

Yes, every pond is an individual when it comes to how it will act in the Winter, or any other time of year, for that matter. Differences include: age, size, depth, filtration, fish load, additional wildlife load, exposure to sun and wind, adjacent terrestrial plant life, amount and variety of the aquatic plant life, and a plethora of other micro-climate variations. Add to this how much fish food gets thrown in the water (any, a lot, none). It all goes together to make up the body of water that is your pond.
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CYA Statement: Every article or blog that we write is based on the rules that we understand in average circumstances in the Greater Phoenix Metropolitan area.  Your pond is an individual, with a unique set of circumstances, so please understand that what we discuss in any of these articles is the rule of thumb and may not be precisely descriptive of what you are experiencing today in your own personal backyard pond.
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With winter temperatures, as the water dips down below 55 degrees (water temperature follows the nighttime temperatures, NOT the daytime highs), we recommend you stop feeding your fish.  In colder water, the fish don’t metabolize high protein food like they do in the summer, and if it goes through their digestive system too slow, it could begin to rot inside them and result in a fish kill.  We get a couple of calls a winter from people who have literally fed their babies to death. It's a very sad thing to have to tell people.
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As always, natural treats like zucchini, melon, lettuce, oranges, and even Cheerios, can be given.
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Your annual cleaning should be done when the water is COLD. So, plan to do that before the end of March. We provide that service, or you can certainly do it yourself.
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Before you know it (and for those of us getting older, it seems to be in the blink of an eye), the water will begin to warm, your fish will become more active, and your aquatic plants will burst forth with new life. Then, we can all start complaining about the heat again...

​Have you ever noticed that your pond water is clearer in the Fall?  This is typically due to cooler temperatures and full, lush plants. To keep your pond looking its best throughout the Fall season, follow our helpful, easy-to-follow pond maintenance tips.

​Prune yellowing leaves off your plants. Your lilies, both tropical and hardy, should still be going strong, and some may even send up the occasional bloom all winter long here in the Sonoran Desert.  Once the plants go into dormancy, leave them alone and don’t prune them back at all until after the last danger of frost has passed (late February, according to the Farmer’s Almanac).

​Stop fertilizing plants, if you’re doing so, when the weather becomes cooler. This lets the plants know the season is coming to an end.

​When the water temperature is around 50 degrees F, stop feeding your fish. If you continue to feed them commercial fish food, you might create health problems for your finned friends, since their digestive systems are beginning to slow down for the winter.  Remember that the water temperature follows nighttime temps.

​As leaves fall from nearby deciduous trees, you'll need to empty your skimmer’s debris net every day to keep up with the influx of leaves. Some leaves will undoubtedly sink to the bottom of the pond; try to remove as many as you can. However, a few left in the pond will give insects and frogs a place to over-winter.  This is also true for the string algae that we get here in the desert instead of freezing over.

​And speaking of string algae, this is something that you might experience during our “winter” months.  If it becomes too unsightly, you can remove it by hand or use a product like Ecoblast. Personally, we prefer to leave some of it in our pond to act as a winter blanket for the aquatic life.

​If you leave too much organic matter in your pond, the water may turn brown. If this happens, remove the excess debris and add activated carbon to clear the water.

​The most important thing is to enjoy your water feature all year long. Keep some of these key maintenance issues in mind, and it will be smooth sailing.  And, if you need any help or advice, we're as close as your phone or email!

The most common causes of this situation in our neck of the woods are either genesis is occurring in a new pond or a storm (or other windy situation) has introduced dust into the water.  If it's the genesis phase, add AquaClearer beneficial bacteria.  Follow the instructions on the package, and back off gradually as long as the water remains clear.  If it's dust, then simply wait until the biofilter has done it's work and cleared up the water.

Again, this could be due to Genesis occurring in a new pond.  It can also be caused by adding fertilizer to plants, or simply over-feeding your fish.  For most causes, adding AquaClearer beneficial bacteria, as described above, will take care of things.  If this situation persists, your pond may need to be drained and checked for foreign material.  This could mean anything from a dead plant or animal that's decaying somewhere within the pond, or simply that the lily you bought and planted came with too much fertilizer for the pond to filter out on its own.

This is most often caused by tannins in the water from the leaves or flowers of a near-by plant, or by the quality of the water filling the pond.  Relax, it's an easy fix.  This is a naturally-occurring phenomenon that is not hazardous to the health of either fish or plants.  However, if this is unsightly for you, you can purchase activated charcoal and add it to the media net found in the Biofalls.  This may need to be replenished occasionally to continue to clean the tannins out of the water.

If the water is just warming up in the Spring, the beneficial bacteria is still in hibernation.  It's also possible that you do not have enough diversity in plant life, are over-feeding the fish, or you are adding fertilizer to plants, etc.  As you can see, several things can be at the root of this problem.  You may hand-weed the algae out of the pond, using it as mulch for your land plants, or in your composting operation, as it's a very nutrient-rich material.  Or you can use String Algae Buster (SAB) to help combat it.  Remember to use POND water when mixing up the dry SAB, and NOT TAP WATER, as tap water contains chlorine, which will kill the beneficial bacterial content.