Effects of Phosphates on Goldfish

Effects of phosphates on goldfish can lead to organ failure

In the past I’ve written about organ failure, and the various substances that lead to the condition, however, I’ve recently learned that phosphates can also be included on the list. Most of us have phosphorus in our tap water, and most of use tap water as our freshwater source for our fish

Phosphates may be higher in some regions due to the mineral being indigenous, however, it’s used to create suds in detergents, shampoos and other soaps we use daily, which leads to higher concentrations in our drinking water. Excluding distilled water, most bottled water contains the mineral

Organ failure in goldfish

Most of the processed fish foods we feed contain some form of phosphates, along with other foods as well, including peas. Peas contain high levels of phosphorus. We knew that peas contained purines, which are hard on the kidneys, but now we have another reason to worry if they are a smart choice. Peas should definitely not be fed as complete diet, as so many do in the industry. I will continue to feed, but in moderation. Peas are leaned on in the industry because they’re high in roughage, and assist in keeping the digestive tract healthy

Safe phosphorus levels are considered as ranging from 0.005 to 0.05 mg/L

I’ve added this tid bit to my article Poisoning our fish, and have started a list of items found in tap water that could poison our fish. Let me know if you can think of other items to add

Most cities have water reports available online

Understanding the water your fish live in will help you help them live longer. Some of us have chloramines in our tap water, which is ammonia and chlorine combined. It’s not uncommon to find nitrates in some city water, but especially if you’re on a well. Old homes with lead or copper pipes could lead to high levels in your tap water; something that may not show on your water report. Allowing the tap to run for 5 minutes before filling the freshwater bucket will help clean most contaminates from the water

Water treatment that converts toxins, metals, as well as phosphates are available at most pet shops, although water treatments should be used with caution. The treatments work by bonding to the agent, making it less soluble. This keeps the fish from absorbing the agent into the blood stream

If you need help reading your water report, post it here. We learn so much from the information provided by our water service department. You can call them if the information isn’t listed. They’re glad to help, and most enjoy the chat


By Venus

Master goldfish keeper


  1. Yes. Numbers, especially decimals, can be very confusing, but in this case, you’re right. Your numbers are low, so no worries there. Another sign you may have high phosphate levels in your tap water is heavy foaming, as increased levels cause suds. This is why we use phosphates in detergents

  2. Hi everyone, I’ve been watching you, but haven’t had much time lately. I did find a water report, and phosphates were listed at .025, so is that okay? I’m lousy at math, but that’s a smaller number than what you have listed in the article, or I think it is

    I appreciate this type of information

  3. Sulfur is actually safe for fish and humans as well, but it stinks. When I was in my early twenties (long time ago) I went to visit a friend in Iowa, and stayed for a week. They had a farm. At the time I was having problems with acne, and also had some rash on my chest and back. By the time I left that farm, my skin was perfectly clear. I was so convinced it was the sulfur, I took several jugs of water back to OK with me. Maybe sulfur has some benefits, or maybe it was the farm life

    It’s fascinating; water is, because it’s so much more than that

  4. You probably have trace amounts; too small for a standard test to pick up, which is normal, and okay. I just recently learned that phosphorus is a necessary mineral for plants, and just about everything we eat contains it, because it’s so common

    My report didn’t show a reading either

  5. Checked my water report, and didn’t see a listing for phosphorus. Does this mean there’s no phosphates in my water? I really appreciate having this information. It’s a hard lesson to learn, but what I keep seeing on this site is true. How healthy your fish are has everything to do with the health of your water

    Thanks Venus

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