Limestone in Natural Rec Pond

[Jrosco34]

I have a question about Limestone used in a large Natural Recreational Pond. I built a 90'x 45' lined pond in 2019. It has a bog filtration system, waterfall with bio filter. I have been having String Algae issues that started about 5 months in from building and this year was a total mess, causing lots of clean up time on a weekly basis. I used limestone in the plant area where the bog filtration system is. The plants are thriving but so is the string algae. I read after the fact that limestone can cause excessive Algae growth. Is this true and if so, is it possible to have eventual success combating algae growth the more the pond gets established or am I just in a bad spot forever? Removing and replacing is not really an option as I have over 30 tons of limestone in the pond. I will say the water clarity has never been an issue, crystal clear.

 

[combatwombat]

1. That is an awesome pond. Looks like a blast to have in the back yard.

2. I think limestone would only "cause" string algae in that it can elevate your ph level, and elevated ph seems to be a precursor to string algae. Have you taken a ph reading on your pond recently? What is it?

 

[Jrosco34]

Yes so the phosphates read almost 0, same with the nitrates. pH will fluctuate throughout the day from 6.5 - 8.5. typically the higher number is the evening reading. Most other number read within average tolerance

 

[brokensword]

Yes so the phosphates read almost 0, same with the nitrates. pH will fluctuate throughout the day from 6.5 - 8.5. typically the higher number is the evening reading. Most other number read within average tolerance

that's a very large pH swing; are you using liquid or strip tests? The liquid is preferable and if your pH is high, you need the 'higher conc' version. I'd actually monitor for a week, morning, noon (if you're home), and night. Track this and see how stable those numbers are. I believe each point is like 10x increase.

As noted on another thread, lime can unlock nutrient uptake in plants, but only for a range of pH; I believe once it hits 8, the effect is much less so. As CW mentioned, lime will raise your pH, that's the main issue to be aware of, as far as I know. And unlike another, lime is NOT a nutrient for algae.

 

[Jrosco34]

that's a very large pH swing; are you using liquid or strip tests? The liquid is preferable and if your pH is high, you need the 'higher conc' version. I'd actually monitor for a week, morning, noon (if you're home), and night. Track this and see how stable those numbers are. I believe each point is like 10x increase.

As noted on another thread, lime can unlock nutrient uptake in plants, but only for a range of pH; I believe once it hits 8, the effect is much less so. As CW mentioned, lime will raise your pH, that's the main issue to be aware of, as far as I know. And unlike another, lime is NOT a nutrient for algae.

Yes agreed those swings are huge. Those numbers were during the height of summer here when I was having massive algae blooms and I was testing it daily both in the morning and evening. I have a liquid test kit that I use, it is the Pond Master test kit. I took a reading this morning and the pH was at 7 currently. I'll check it again tonight and the rest of the week to get a new reading.

 

[mutai]

Yes agreed those swings are huge. Those numbers were during the height of summer here when I was having massive algae blooms and I was testing it daily both in the morning and evening. I have a liquid test kit that I use, it is the Pond Master test kit. I took a reading this morning and the pH was at 7 currently. I'll check it again tonight and the rest of the week to get a new reading.

Hey, would love to find out what you did eventually and if it was in fact the limestone that was causing this.

 

[GBBUDD]

@Jrosco34 this post is three years old . And I have not seen the person who started this thread since then.

 

[j.w]

@mutai

 

[GBBUDD]

@mutai this post is three years old . And I have not seen the person who started this thread since then.