How often & Phosphates

[MariaTeresa]

How often should we check the water parameters?

Also, is there a natural way to remove phosphates from the pond? My water consistently reads at 1ppm (and has the string algae to prove it).

Thanks!

 

[Rach]

I have been suffering with blanket agae for months. I have hardly anything rotting on the bottom. Have a fish feeder so can remove any unwanted fish food. I resorted to a product called STOP Blanket weed. 2 weekly doses and it has reduced dramatically. I have also on daily basis been removing by hand any new growth I can get too. The product says apply 3 weekly times and once a month. Cost £20.

 

[Meyer Jordan]

PhosOut or similar binders are the most efficient way of reducing high Phosphorus levels.

 

[MariaTeresa]

But where do the phosphates come from, and in a balanced ecosystem what would be removing them?
PhosOut would work as a one time thing, but is there a long term solution?

 

[Meyer Jordan]

But where do the phosphates come from, and in a balanced ecosystem what would be removing them?
PhosOut would work as a one time thing, but is there a long term solution?

Phosphorus comes from many sources, mineral and organic. For our purposes, as Pondkeepers, the primary source of Phosphorus is fish food, uneaten or digested. In a garden pond, Phosphorus levels will rise over time because P is the secondary nutrient required by plants and most algae, excluding filamentous.. Nitrogen, in the form of Nitrate, is the primary nutrient. In other words, due to supplemental feeding being the norm, P is added to the water column faster than plants and algae can assimilate and utilize it. Once P reaches a certain level (>0.05 ppm), it will readily sustain the rapid growth of filamentous (string) algae.
The long term solution for controlling high levels of any organic or chemical item is limiting how much is added to a pond from external sources. There are products on the market such as PhosBan that will maintain P at levels less than 0.05 ppm. One application is usually sufficient for several months. For absolute control only a reduction in fish population and/or feeding levels is a permanent solution.

 

[MariaTeresa]

For our purposes, as Pondkeepers, the primary source of Phosphorus is fish food, uneaten or digested.

Hmm. I don't feed my fish at all, so it can't be coming from fish food. Maybe I need to test the tap water and see if it is coming from there.

PhosBan sounds like a better solution than PhosOut, I'll look into that. Thank you, Meyer!

 

[Meyer Jordan]

PhosBan is indicated for use on Phosphorus at low levels <0.05 ppm. PhosOut is indicated for use on Phosphorus at higher levels >0.05 ppm. An accurate level of existing Phosphorus must first be determined by testing.
At 1 ppm, PhosBan would have no effect. I really have to question this 1 ppm level. This is extremely high. Are you certain that this is not 0.10? Which test kit for P are you using?

There are many other sources of Phosphorus other than fish food. Leaves, pollen, grass clippings, dead insects, animal feces.....anything organic will contain a certain level of Phosphorus.

 

[MitchM]

Harvesting excess algae and plant growth is another way to remove phosphorus from your pond.
Put the harvested material in your garden.
Phosphorous promotes root growth and flowering
I have found that our hobbiest test kits are best for indicating a trend in tested levels. I wouldn't rely on the test kits to be all that accurate for the actual number.

 

[MariaTeresa]

Meyer, I use the API Pondcare Master Liquid Test Kit. It is definitely 1, half-way down the card. It has not increased or decreased. Animal feces rings a bell....there are a lot of birds that use the pond to bathe and a lot of droppings get in. Pollen is not an issue at this time of year (earlier I get 3 days or so of spruce pollen blown in). Our workmen did blow the grass clippings into the pond the other day, but they ordinarily do not and I still have the same reading. I do have an outstanding number of aphids on my water hyacinths (thanks to an ant colony by the pond) and a little on the lily pads. I knock the lily pad ones into the water, so if they don't get eaten maybe that's an issue.

Mitch, what do you mean by harvesting plant growth? My plants are still getting established, so I think I wouldn't want to disturb them, right? I thought the more plants the better the water quality.

I pull out yellow leaves/lily pads. There is some dirt in the bottom from an incredibly severe thunderstorm a few weeks ago. I don't ordinarily have a problem with run-off....or at least I thought so. Maybe the Phosphates are telling me differently.

 

[Meyer Jordan]

Meyer, I use the API Pondcare Master Liquid Test Kit. It is definitely 1, half-way down the card. It has not increased or decreased. Animal feces rings a bell....there are a lot of birds that use the pond to bathe and a lot of droppings get in. Pollen is not an issue at this time of year (earlier I get 3 days or so of spruce pollen blown in). Our workmen did blow the grass clippings into the pond the other day, but they ordinarily do not and I still have the same reading. I do have an outstanding number of aphids on my water hyacinths (thanks to an ant colony by the pond) and a little on the lily pads. I knock the lily pad ones into the water, so if they don't get eaten maybe that's an issue.

Mitch, what do you mean by harvesting plant growth? My plants are still getting established, so I think I wouldn't want to disturb them, right? I thought the more plants the better the water quality.

I pull out yellow leaves/lily pads. There is some dirt in the bottom from an incredibly severe thunderstorm a few weeks ago. I don't ordinarily have a problem with run-off....or at least I thought so. Maybe the Phosphates are telling me differently.

 

[Meyer Jordan]

If that truly is the test results, then I must question the accuracy of that test kit. Fresh water with a P level of 0.10 ppm is considered polluted by the U.S. EPA.
Some test kits require a conversion factor to equate Phosphate with Phosphorus. This is normally a factor of 3. Since the API kit measures Phosphate the results would be divided by 3 to get Phosphorus levels. Even assuming that this conversion is applicable to API test kits, this would still leave a Phosphorus level of 0.33 which is over 3 times the recommended EPA maximum.
How old is you est kit?

 

[MariaTeresa]

The kit is less than 2 months old.

I tested my tap water and it was almost 1.0ppm. A little lighter in color than the pond result, but still matching the 1.0 color on the card. The booklet that came with the kit said that phosphates are sometimes added to city water to deal with heavy metals and prevent corrosion of pipes. Apparently they are added to our water here.

Since the phosphates are coming from the water I add to the pond, it looks like PhosOut is really my only option.

 

[MariaTeresa]

I've ordered Clear Pond Phosphate Remover. Hopefully that will bring the level down. I really need to find a cheaper long term solution. Maybe there is a plant that removes phosphates?

 

[Meyer Jordan]

Call your local Water supplier (city) and verify the Phosphate levels in the tap water. They should be able to tell you the exact level of Phosphate that they are trying to maintain.
The only living thing that I know of that removes P at those levels is, you guessed it, filamentous algae,

 

[MitchM]

Your best phosphhate remover is the algae.
What might work is to keep the algae growing in areas of high water flow and remove it from areas where it is unsightly or could clog your water pump.