Sodium percarbonate uses in fish ponds

[zek]

Roddy,

Does Baquacil/HP increase PH like SP?

I like using SP, but don't like going up in the 9's for PH.

[Roddy Conrad]

Hydrogen peroxide as Baquacil (27% strength) or simple generic 3% hydrogen peroxide from Walmart (and lots of other places) has no significant effect on pond pH. Sodium percarbonate does usually increase pH significantly, that can normally be resolved by addition of calcium chloride flake if the pH is too high from sodium percarbonate use.

[zek]

Thanks Roddy, that's good to know.

I always use calcium chloride with the SP, but it seems like the PH was always close to 9. This last year the pond has settled out and I only did an initial cleaning with SP and have not had any other issues. I think I'll go with the Baquacil next time.

[IMPALA]

I wrote this in a private message then decided to post it since the comments may be useful to others.

Assume 4000 gallons pond volume and 27% hydrogen peroxide to calculate the dose.



4000 gallons times 8.3 pounds per gallon times 454 grams per pound gives 15 million grams of water in a 4000 gallon pond so a 1 ppm dose of something is 15 grams of the thing. At 27% strength of Baquacil oxidizer, to get an active dose of 1 ppm active hydrogen peroxide will require 15 grams /.27 = 55 grams of the Baquacil oxidizer.



But we want enough hydrogen peroxide to see some algae die.



At 25 ppm active hydrogen peroxide dose for 4000 gallons we need 55 times 25 = 1,375 grams or over a liter of the Baquacil oxidizer to kill some algae. I suggest you be conservative and at first only add half a liter of the 27% strength or two cups. If that does not seem to do anything, add two more cups in a few hours.



The LC50 (Lethal concentration that kills half the fish) for a two hour interval is 1000 ppm which would be several gallons of the Baquacil oxidizer in 4000 gallons. The 24 hour LC50 is 100 ppm which is 5 liters or a little more than a gallon per 4000 gallons. One ponder actually dumped a gallon of the Baquacil oxisizer into his 4000 gallon pond, in a few days a few of the koi died from the overdose. So that is too much. The 4 day LC50 is 25 ppm or a dose of 1.375 liters or about a quart and a half. That is relatively safe and will kill a lot of algae in a 4000 gallon pond. 25 ppm dose in an algae ridden pond should be consumed before it does any fish damage. If you are adventursome and want the algae dead in a hurry, use that dose. If you are terribly conservative, try doses of two cups at a time spaced half a day apart until the algae comes under control.



Roddy

thanks Roddy

[minesh1]

So you'd want to add 100ml/1000gal each day for several days without water changes? Do you recommend a water change at the end of the treatment?

[nedleigh]

So I used the sodium percarbonate basically at the bottle label dose for the branded sodium percarbonate for algae control

Then I discovered that strong hydrogen peroxide is available everywhere and very cheap when labeled as Baquacil oxidizer for swimming pools and spas. Okay, that is even cheaper than generic sodium percarbonate, and has the advantage that it does not drive the pH high, which sodium percarbonate certainly does.

If this is not clear, please ask questions! What is clear to me is seldom so clear to non-chemists!

Okay, so I've read this whole thread through for the second or third time, and I thought I understood things reasonably well, but now I'm back to confused.....

My take was that the various forms of string algae control being discussed here were all pretty much different implementations of sodium percarbonate, i.e., hydrogen peroxide. Whether it's Baquacil or Oxiclean or walmart 3%, the differences and preferences expressed are based on price per dose, convenience and what's available. (The sodium perborate is a slightly different case, but I'll leave that to the serious chemists to hash out....) For instance, my read between the lines is that Roddy likes the Baquacil because it is readily available near his house, meaning that it's effectively cheaper because there are no shipping and hazmat charges.

I was under the impression that sodium percarbonate is a solid form of hydrogen peroxide, yes? If I'm following the math right, generic SP works out as 98% hydrogen peroxide. But based on the mention of the pH movement above, I get the feeling that Baquacil Oxidizer (which is basically 27% strength HP, yes?) is somehow a different animal?

I can't seem to find Baquacil locally (on my little island here in the middle of the Pacific), so the next best thing I was able to locate was Oxiclean Free. (As far as I can tell, they reformulated a lot of the Oxiclean line in 2005 to include detergents, surfactants, perfumes, etc. The Free version seems to be the original formulation, which consists only of sodium percarbonate and sodium carbonate. According to the MSDS, the SP content is "50 - 70%" and the SC is "30 - 50%" - that's a rather broad range!)

Since my noobie pond set up allows me to isolate my fish from the water garden part where I was having a massive string algae outbreak, I decided to give the Oxiclean a try. I tried dosing at 25 ppm in two stages (4 oz and then another 4 oz into 1400 gallons over the course of a couple of hours) but nothing really floated to the top and I didn't see any fizzing even when I dropped the stuff directly onto the algae. I brushed down the pond and scooped up what I could, then was going to do a 25% water change afterwards. I noticed a fair amount of foam in the discharge water, so I drained it all and filled it with fresh (which amounted to a 50% water change), since I was concerned that there might ingredients not mentioned in the MSDS that were less than fish friendly.

Did I completely mis-read all this excellent info? Am I just a confused noobie? Any clarification would be appreciated......

[Roddy Conrad]

Okay, so I've read this whole thread through for the second or third time, and I thought I understood things reasonably well, but now I'm back to confused.....

My take was that the various forms of string algae control being discussed here were all pretty much different implementations of sodium percarbonate, i.e., hydrogen peroxide. Whether it's Baquacil or Oxiclean or walmart 3%, the differences and preferences expressed are based on price per dose, convenience and what's available. (The sodium perborate is a slightly different case, but I'll leave that to the serious chemists to hash out....) For instance, my read between the lines is that Roddy likes the Baquacil because it is readily available near his house, meaning that it's effectively cheaper because there are no shipping and hazmat charges.

I was under the impression that sodium percarbonate is a solid form of hydrogen peroxide, yes? If I'm following the math right, generic SP works out as 98% hydrogen peroxide. But based on the mention of the pH movement above, I get the feeling that Baquacil Oxidizer (which is basically 27% strength HP, yes?) is somehow a different animal?

I can't seem to find Baquacil locally (on my little island here in the middle of the Pacific), so the next best thing I was able to locate was Oxiclean Free. (As far as I can tell, they reformulated a lot of the Oxiclean line in 2005 to include detergents, surfactants, perfumes, etc. The Free version seems to be the original formulation, which consists only of sodium percarbonate and sodium carbonate. According to the MSDS, the SP content is "50 - 70%" and the SC is "30 - 50%" - that's a rather broad range!)

Since my noobie pond set up allows me to isolate my fish from the water garden part where I was having a massive string algae outbreak, I decided to give the Oxiclean a try. I tried dosing at 25 ppm in two stages (4 oz and then another 4 oz into 1400 gallons over the course of a couple of hours) but nothing really floated to the top and I didn't see any fizzing even when I dropped the stuff directly onto the algae. I brushed down the pond and scooped up what I could, then was going to do a 25% water change afterwards. I noticed a fair amount of foam in the discharge water, so I drained it all and filled it with fresh (which amounted to a 50% water change), since I was concerned that there might ingredients not mentioned in the MSDS that were less than fish friendly.

Did I completely mis-read all this excellent info? Am I just a confused noobie? Any clarification would be appreciated......

You got it pretty much right.

SP or sodium percarbonate quickly hydrolyzes to hydrogen peroxide and sodium carbonate. Since sodium carbonate drives the pH up, use of SP provides a lot of hydrogen peroxide but tends to drive pH into the 9 to 10 range, which many folks don't like.

Enough hydrogen peroxide kills all forms of algae, too much of it can eventually kill fish, but that does not often occur since algae laden ponds rapidly consume hydrogen peroxide.

[Joey S]

Hey Roddy...got a local pond with a major algae problem - specifically - Oscillatoria. This is a big public facility. oooohhhh, I don't think I'm ready to take this on, but if you help, I'll gather all the info. Could be a good learning experiment.

Lots of basic problems to deal with...major water changes and water disposal. Source water with phosphates. Shallow water. Full Sun. Low oxygen levels. Lots of fun things to deal with.