plants slowly dying/disappearing

[pafek]

for the last year or so I have been having trouble maintaining the plants in my pond. They seem to slowly die off- even duckweed and salvinia, which I used to have to scoop out of the pond to get rid of it. I have some water lilies that are growing, but do not seem to be really thriving. The fish in the pond are fine, the water has some algae on occasion, but is reasonably clear. The usual tests (ammonia, nitrites, pH, nitrates, etc) are usually OK. Any ideas?

 

[addy1]

maybe not enough fish poop? Put some plant tabs in your lilies see if that helps. Are they in gravel, bare root or dirt?

what kind of sun does your pond get

and welcome! to the group

 

[pafek]

maybe not enough fish poop? Put some plant tabs in your lilies see if that helps. Are they in gravel, bare root or dirt?

what kind of sun does your pond get

and welcome! to the group

thanks for the welcome! The lilies have plant tabs I pushed into the soil (mostly sandy soil in pots), the rest of the plants are free-floating, such as water lettuce, duckweed, and foxtail. I have thought about adding some fertilizer to the water, but I am worried it will cause the algae to get worse. It's strange that for all these years I had to rip out excess plants that would try and take over the pond, now everything looks sort of punky. The pond does get somewhat less sun than it used to, as there is a tall stand of bamboo that has been growing next to it, but it still gets sun for 6 hours a day or more. As it is already over 100 degrees here, that is plenty!

 

[addy1]

i would not add fertilizer to the water, you could take them out of the pond, float them in a small container with fertilizer then put them back into the pond. Something like miracle grow.

ph hardness etc all the same?

 

[DrDave]

How about circulation? Standing water does not promote plant growth as well.

 

[vertigo72]

The usual tests (ammonia, nitrites, pH, nitrates, etc) are usually OK. Any ideas?

Did any of these values change significantly compared to last year(s)? Also, what do you measure, particularly for nitrates and GH? "OK" is a vague term. Perhaps the water has become too soft and/or too acidic due to dilution by rainwater?

 

[pafek]

Did any of these values change significantly compared to last year(s)? Also, what do you measure, particularly for nitrates and GH? "OK" is a vague term. Perhaps the water has become too soft and/or too acidic due to dilution by rainwater?

I really wasn't checking chemistry much in the past, as the pond did very well on autopilot. After I started having problems with a few fish dying and with plants disappearing I started checking. The pH has been 7.0-7.5, I had some ammonia but not much nitrite or nitrate. Now that my new filter and pump have been colonized I'm getting more nitrates- which should help the plants. I just cleaned out almost all of the muck at the bottom of the pond, which necessitated a large water change, and I just put in a lot of assorted plants- I'll see what happens!