Water Changes...Unnecessary?

[nishikigoi21]

So we know the purpose of water changes are to reduce nitrate levels in a tank or pond...but I always thought it was to also dilute the organic matters in the water(oil from food, fish urine, etc.)

My tap water has 40ppm of nitrates to begin with, so am I wasting water & money if I perform a water change in a pond that has 40ppm of nitrates?

I even have floating plants and a bakki shower filter so sometimes the nitrate level is lower in the pond than the tap. Should I completely stop or lower the amount/rate of water changes?

Oh, the tap also has 2ppm of ammonia due to chloramines...

 

[Deadliestviper7]

So we know the purpose of water changes are to reduce nitrate levels in a tank or pond...but I always thought it was to also dilute the organic matters in the water(oil from food, fish urine, etc.)

My tap water has 40ppm of nitrates to begin with, so am I wasting water & money if I perform a water change in a pond that has 40ppm of nitrates?

I even have floating plants and a bakki shower filter so sometimes the nitrate level is lower in the pond than the tap. Should I completely stop or lower the amount/rate of water changes?

Oh, the tap also has 2ppm of ammonia due to chloramines...

Do water changes as it removes pheromones that fish produce, if these chemicals are left in the water it inhibits growth.

 

[skjl47]

so am I wasting water & money

hello; One point of the hobby is to "waste" money and water for something (fish) we do not need. Your stated problems are likely to be more expensive to fix that those blessed with good water.
Hello; Even with your source water as stated there is at least one other reason for WC. That being in a closed system such as a tank or pond without and inflow and out flow there will be a build up of minerals, mineral salts and other dissolved compounds due to evaporation. If you only top off a tank then the concentration will increase over time.

 

[nishikigoi21]

That makes sense, thank you.
I just felt guilty doing it when the nitrate levels in the pond water are half that of the tap...

 

[skjl47]

That makes sense, thank you.
I just felt guilty doing it when the nitrate levels in the pond water are half that of the tap...

Hello; Also bear in mind we can test for a few things including nitrate, ammonia, nitrite, dissolved oxygen, pH, TDS (solids) and a few more. A few decades ago I included a section in my classes about all the chemical compounds created each year.

At one point back in the 1980's I think it was estimated the chemical labs were on a path to create as many as 3000 in an average year. Of course not all found their way into consumer or commercial products but many have. I saw an estimate recently that there may be tens of thousands ( maybe 30,00 or more) released into the environment over time. Some degrade over time while some are persistent. Some are going to be sort of neutral, at least in a reactive sense but may still have a physical presence. Some will turn out to be bad in a reactive way of course. And some may be of benefit. A point being we do not know all the ramifications before these things are used. We are in essence testing many of these new compounds on ourselves at a global scale.

Another point is that even the tap water companies do not have the capacity to test for the majority of the stuff in our water. I saw a program recently showing a mass spectrometer result of various tap waters. There were many spikes with each spike representing a compound but few can be identified. Sorry about all that but this issue alone, to my mind anyway, makes a piker of Global Warming (GW). I find several other issues to be greater than GW.

Throw some non rooted live plants in the pond. They should grow well with high nitrates. Then harvest the plants on a regular basis. During a WC try to siphon out as much organic detritus as you can.

Best may be to get a different source water.

What is the general condition of the fish? If they are doing ok and not being sick or prone to die at high rates then do what you can.

 

[esoxlucius]

In an ideal hobbyists world all our water sources would be 0ppm nitrate. A lot of us are fortunate enough to have 0ppm as a starting point for our water changes. But of course in the closed loop environment of an aquarium those nitrates rise, some faster than others. I let mine rise to about 20-30ppm before i do a water change, and that is once per week. Others do it before that level, some after that level.

For you, and many many others who have been dealt a bum deal with their water sources, you still have to keep well on top of your water changes because the same principles apply. By the time it's water change day for you i'm guessing that your nitrates could be anywhere from 60-100ppm, even more.

Basically, my ultimate goal is for constant 0ppm nitrate but unless i do water changes every day i'll never achieve that, not on my current set ups anyway. Your ultimate goal is to achieve 40ppm nitrate, again something that you'll never achieve unless you do water changes everyday. Or completely overhaul your system (drips etc).

So keep up those water changes. You may feel like your pissing against the wind but in fact you are most certainly not. You are doing your fish a great service. Plus, on a more positive upbeat note you could always research areas that have 0ppm water sources........and move there!!!

 

[Stephen St.Clair]

Besides all the above listed advantages of regular WC's, another important aspect is the dilution of parasite and
Infectious bacteria populations that are ever present in all aquariums.

 

[squint]

Nitrate is essentially non-toxic to adult fish so fear of nitrate toxicity shouldn't be the reason you do water changes.

 

[RD.]

Nitrate readings are simply used as a gauge to assist one in keeping their overall parameters in check. Generally speaking, a high nitrate reading equates to other issues, such as possibly a high bacteria count from excess waste in the system. High nitrates may not be toxic, but many things found along side those high nitrate readings can result in disease and even death.

 

[squint]

There's really only ever been one long-term nitrate toxicity study:

Ammonia Toxicity Levels and Nitrate Tolerance of Channel Catfish

In the nitrate study, nitrate build-up in the holding tank of the Aqualoop system over a period of 164 days was observed (fig. 2). The observation began on July 27, 1971, with approximately 35 3-inch largemouth bass in the holding tank. The nitrate level was 170 ppm at that time, and over the next 30 days, 10 of the bass died from unknown causes. The bass population stabilized at that time and the nitrate level, which had been decreasing as the number of fish decreased. began to rise as the bass began to grow. By November 6, 1971, the nitrate level had reached 300 ppm with seemingly no effect on the fish, which appeared very healthy, and showed no gross signs of disease nor any lethargic behavior, and reached 5 inches in length. On that date, 200 4. to 6-inch channel catfish were added to the system to increase the rate of nitrate build-up. All 200 fish survived the transfer and were on full feed within 1 week. One month later 100 of the catfish were removed for the ammonia test, but of the remaining 100 catfish and 25 bass, none had been lost when the observation ended on January 6, 1972, with the nitrate level at 400 ppm. At that time many of the bass were approaching 6 inches, and while it was difficult to determine individual growth of the catfish, the larger individuals had reached 7 inches in length. From these observations, it appears that nitrate levels as high as 400 ppm can be tolerated by channel catfish and largemouth bass without significantly affecting their growth and feeding activity.

A lot of studies simply add sodium nitrate or potassium nitrate to the water. This one let nitrate levels build-up naturally so it would include all those "other" unmeasured toxins.