Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Phoslock

Has anyone used this? Review?

http://www.phoslock.com.au/faqs-usa.php#2

What are you trying to achieve ?

Any other forum info on this? Sounds like a good product if it actually works.. It locks up and removes phosforus from the water column.. Which I think is one of the main contributors too FA??

I could not get that link to open but here is what wikipedia has to say about it. Some form of Bentonite:

http://en.wikipedia.org/wiki/Phoslock

It does have bentonite in it.. Here's a link with a little info no real details though..


http://www.sepro.com/phoslock/

Here's the link: http://www.sepro.com/phoslock/Default.aspx

I bought some Phoslock quite a while back but I haven't used it yet. There's quite a few studies on it, look in the left hand menu for case studies.

And this:
"Phoslock is an environmentally compatible and effective solution in a wide range of water chemistries in ponds, lakes and reservoirs. Phoslock programs require no buffer to protect water quality and aquatic life during and after application."

Here's some more info..

http://www.sepro.com/documents/Phoslock/TechInfo/Phoslock%20Technical%20Bulletin.pdf

I'm interested but I'd like to hear some thoughts from Bill Cody, Rainman, ewest, even Bob lusk to see what the pros think of the concept as a whole..

Yep, that's the link. There is a lot of information if you look at the left hand menu.

I bought the Phoslock because I don't want to put alum in my pond. I have dogs that stir up the bottom and drink the water so I was concerned about alum.

"All forms of alum can cause irritation of the skin and mucous membranes. Breathing alum can cause lung damage. Aluminum also may attack lung tissue. Because it's a salt, eating massive amounts of alum can make you sick. Usually ingesting alum will make you vomit, but if you could keep it down, the alum could upset the ionic equilibrium in your bloodstream, just like overdosing on any other electrolyte. However, the primary concern with alum is longterm exposure to low levels of the chemical. Aluminum, from your diet or healthcare product, can cause degeneration of nervous system tissue. It is possible exposure to aluminum could lead to an increased risk of certain cancers, brain plaques or Alzheimer's Disease."

Loretta:

Read this:

http://www.phosclear.com/downloads/NALMS%20Position%20Paper.pdf

Yes, that's one groups position but not mine. You can find a study to back up any position if you like. I feel more comfortable using Phoslock based on my research.

The EPA is referenced in the article and they also allow fluoride in drinking water which has an "adequate margin of safety". I use bottled water for drinking and cooking and prefer to not drink water with chlorine or fluoride on a long term basis. To each their own, I don't believe my concerns are irrational.

Loretta,
I am currently in the process of using Phoslock to reduce phosphorus levels in my 1 3/4 ac. pond. My water was tested and revealed a level of 214 mg/L. That's 20 times what is considered normal. I've applied 1/2 of the recommended amount of Phoslock. Yesterday, I sent another sample for testing to see what effect it had on free reactive phosphorus and total phosphorus. The product is not cheap so I am curious about it's effectiveness. I have re-routed my incoming water so no additional runoff enters the pond between applications. The source of the phosphorus load is an agricultural field.

Loretta...that quote sounds like it is from some of the fear mongers out there. Alum (AlSO4) is a GCS chemical, generally considered safe. Toxicity in a pond can only occur if the pH drops to 5.4 or below to allow the aluminum to become soluable. Alum has/had been used as an anti-perspirant for decades as well as being used in virtually every public water supply until more effective polymers were created to clarify and remove solids.

The "claims" made in your fear quote are what could happen in a concentrated setting, and not because of the aluminum, but because it is a mildly corrosive acid only. In a pond, heavily diluted, it is VERY safe.

Loretta - the cautionary statement is for ingesting or eating lots of powdered alum when it is airborne. Eating it applied to eating massive amounts. Similar warnings apply to bentonite that evidently is used in Phos-loc. The same warning applies to taking too many vitamins and a lot of other products. Aspirin and other good for you products can be problems if taken in massive amounts. If you drink 3-5 gallons of water per day it can kill you. When alum is dissolved in water the hazards are minimized when used correctly.

This is from the MSDS for bentonite:
Appearance: cream to gray brown powder.
Warning! Causes eye, skin, and respiratory tract irritation. May cause cancer based on animal
studies. Hygroscopic (absorbs moisture from the air). The toxicological properties of this material have
not been fully investigated.
Target Organs: Respiratory system, eyes, skin.
Potential Health Effects
Eye: Causes eye irritation. May cause chemical conjunctivitis.
Skin: Causes skin irritation.
Ingestion: Ingestion of large amounts may cause gastrointestinal irritation. The toxicological properties
of this substance have not been fully investigated.
Inhalation: Causes respiratory tract irritation. The toxicological properties of this substance have not
been fully investigated. When inhaled as a dust or fume, may cause benign pneumoconiosis. Can
produce delayed pulmonary edema.
Chronic: May cause cancer according to animal studies. Effects may be delayed. Chronic inhalation may
cause lung changes, chest pain, breath shortness, and bronichitis.

I think Loretta really just wanted to know if anyone had any experience with Phoslock. :-)

I agree.. I'd like too know the same

Ask me again later on this year. I just might have used it in a clients pond by then.

Thank you.

Not using Alum is my choice. I also prefer to not drink out of aluminum cans even though it's considered safe. It's my choice, if you prefer to drink out of a can it's your choice, I wouldn't try to convince you otherwise.

Bentonite is an FDA approved food additive and "very little if any is absorbed after oral administration". Chronically inhaling bentonite is another matter and could carry a risk but that's not my intent.

Phoslock is a lanthanum modified bentonite. Lanthanum carbonate is an oral drug (Fosrenol) that is used in patients with end stage renal disease because it binds phosphates. Ingestion of lanthanum has been widely studied and the FDA approved human dose is up to 3000 mg/day, a long way from a 50-80 ppm application rate in a body of water.

After an application of 1/2 of the recommended dosage of phoslock,the last water sample indicated Free Reactive Phosphorus of 13.0ml/L Down from 23.60ml/L. Total Phosphorus was 81.6ml/L. Down from 214ml/L. I'm taking one more water sample to verify the results before making the final application.

I'd like to hear actual results on pond overall quality after using.. Particularly FA growth rates..

Verdehoy thanks for posting your 1/2 application results, I somehow missed your post the first time around. Do you have an update?

I haven't used my Phoslock yet but I will be applying it in the next week or two. How did you get it added to your pond? Any advice would be helpful. Do you run an aerator and if so when did you turn it on, during application or after? My pond is small 1/4 SA, 13' deep at full pool and I aerate.

TIA

Found these more recent videos on youtube:

http://youtu.be/nWO7DwCGwf4 (length 2:27)
http://youtu.be/dn86YR3pu2w (length 3:44)
http://youtu.be/8VbIwdlJ26I (for aquariums! length 2:34)
http://youtu.be/zje5vrTfmWk (site study, length 15:18)

Loretta, let me know how it goes. I just picked up slightly more than 700# for a client of mine.

If the recommended application thickness is what is shown on the first video in the core sample I would have to add major tonnage to my almost 4 acre pond.. I like the concept and it seems promising..

It all depends on the Ortho P reading how much you need. If you can get alum and hydrated lime, I'd look into going that route first due to costs involved. Price PhosLoc and you'll see what I mean. I know PhosLoc is slightly different than alum/hydrated lime, but I'd like to see an honest side by side test to show whether PhosLoc works better.

It's calculated on acre foot of water, not strictly surface acres.

Read this, you might find what your looking for:
Comparison of P-inactivation efficacy and ecotoxicity of Alum and Phoslock

Interesting how someone with a competing product states how poor the alum approach is. They cite alum being most effective at pH 4-6 and how it's quite ineffective at pH8. And Al toxicity to fish, but they admit toxicity isn't much of an issue unless pH less than 6.5.

The anecdotal information here says alum generally works. Perhaps it is less efficient than it could be. We know we need to manage pH. They say alum treatment is worse because buffering for pH can cause rapid changes, but we know to take it easy.

They cite that alum can require application of 2-10x more material than lanthanum. That's nice, unless the La costs 100x.

I found the document very one-sided. While the benefits of their product may be true to some degree, how much can I trust their assertions if it's just a sales brochure? They never try to present application information for the common lake manager to decide what's best for them.

Loretta, I have made applications of phoslock to my pond and have had good results. First , have your water tested for free reactive phosphorus, not just total P. Note: it can be difficult to find a lab that can do this. Phoslock requires constant agitation to distribute evenly. Your aeration system will aid in mixing once it's applied. I applied 1/2 of the phoslock and then tested the water before adding the second half. You really don't want to eliminate all P. The bottom of the food chain needs some to thrive. Alum/hydrated lime was effective also but was costly also because it took a special spray boat to apply. Identifying and reducing or eliminating the source of your P load should be considered to avoid future applications. The folks at seapro have been very helpful through this learning experience and were honest about what it can and can't do. I also manually remove primrose from my water so there is no recycling of those nutrients.
Note: I am no pond pro. I also have no bias for one product over another. They both work but I can apply the phoslock myself.

How did you apply the phoslock?

Mixed in a 30 gal tub and pumped it out with a 1 in. pump stirring constantly. I tried to cover the entire surface. 1.7 ac. BOW

Thank you, wow, that doesn't seem like much volume to cover 1.7 ac! I was worried about coverage using a 55 gal drum on 1/4 acre.

I just mix a few lbs at a time. I applied 8 bags to 1.7 ac.

I'm planning to pump Phoslock over my 1 acre pond here in NJ at the end of April. We've only had one or two warm sunny days, but it is already turning quite green. I will let you know the results.

The study from Phoslock seems rather biased, saying Alum is pH driven while Phoslock isn't, yet going on to say "optimal" in a 6-9 pH....sounds pH driven just like Alum to me... Since I happen to know that alum is also "optimal" at slightly a lower pH range, yet works outside those ranges...that comparison alone is misleading, if not intentionally false. As far as toxicity, pH has to drop to 5.4 before aluminum dissolves and can become toxic...a level that is lethal to most fish anyway, so rather irrelevant in a sport-fish setting.

Other things that stood out to me were words like may, or might when referring to phoslock and not with alum in binding phosphorous permanently and becoming a barrier to sediment based phosphorous...again, very misleading to most casual readers looking for solutions to high levels of phosphorous.

Alum, (AlSO4 or Aluminum Sulfate) is classified as a GCS (Generally Considered Safe) chemical by the FDA and for years, was used in virtually every municipal water supply in the world. A rash of reports once claiming links to brain disorders, like alzhiemers, have all been debunked and proved false.

I think Phoslock is a product that works, yet not as well, permanently, or at a nearly the cost-effective price as Alum.

For me, the report linked to is a prime example of "outcome based research"...stating facts in a way that only support a desired conclusion while ignoring, or trying to minimize, facts that could oppose the desired conclusion.

Was the Phoslock treatment successful in knocking down the phosphorous levels and controlling planktonic algae? My problem is really green water and blue green algae in August. Thanks!

Hobart, I had green water problems also. It seems that you have two choices. You can find a lab to do the testing and quantify your results or, you can just wing it and guess at the correct application rate until you get the desired results. I applied half of the recommended amount and re-tested to confirm its effectiveness. I have used phoslock and phosclear and have had good results with both. The alum/hydrated lime application that was done on my pond was for a suspended clay issue and worked very well for that. None of these options are cheap. I still have a small patch of FA here and there but it is not a problem. Eliminating the P source seems to be the best medicine.

Hi all, have been looking at Phosclear application for my 7 acre lake. Website says it is a powder and just sprinkle it on the water, no need to make a slurry. No mention of adding lime. I was thinking I could apply over top of the Vertex diffusers, letting them do the distribution. Big project, but there doesn't seem to be a reasonable company to hire around here. Any thoughts/experience greatly appreciated. Thanks.

Hire Rainman to do an aluminum sulfate/hydrated lime application. Basically the same thing for less $$.

I have a client that has roughly 30 surface acres of water that is nutrient heavy. I'm trying to get them to spend the money to do a nutrient reduction program, and he is who I'd call to do the application.

A quick look at the pricing on the name brand product mentioned showed to be $120 for 40 pounds...also claims to treat 1-2 acre feet. The name brand product is priced at $3/lb...Alum/Hydrated lime is the exact same effective result at ~1/3 that price per pound, applied.

Also, a treatment rate as described for the name brand is between 20 and 40 pounds per acre foot of water volume. Even for simply binding Phosphorus, and not also clearing colloidal clay, I have never seen, nor heard of, an application rate under 100 pounds per acre being effective. If only 40# per ac/ft were needed, I highly doubt you'd have a vegetation issue needing addressed to begin with.

In fact, to emphasize that you will likely need at least 3 times what the website claims per acre foot....The Koi pond shown on the company website says 1.5 pounds of phosclear is applied to 5500 gallons...that is a .0272% concentration. At a 20 to 40 pound per acre foot rate as described/recommended on the product website, 40 pounds equals a .0122% concentration and at 20 pounds per acre foot, only a .0061% concentration.

A .03% concentration is close to the bare minimum concentration needed to create the chemical reaction required for effectiveness.

Rex, I applied 880# to a 3/4 acre pond, 8' depth max. It cleared the water up pretty well, but I would have preferred to use alum/hydrated lime. Just no way to get the equipment to the pond due to the manicured landscape surrounding the pond.

I wonder how well it would work if I applied the phoslock over a frozen pond? I'm thinking a regular fertilizer spreader would work but not sure if the product would stay stabil as the ice thawed??

Todd, since the best results will be obtained by evenly and proportionately spreading the product, it would probably take far more product, spread on ice, than it would normally for equal results. I could be wrong, but having cleared many ponds in various ways, I have found broadcasting Alum/Hydrated Lime, it takes at least 3 times the product as other methods to get the desired results.

Phosloc is a LOT more expensive than alum/hydrated lime

Scott, I fear that blue-green algae (BGA) is not just a hazard to the fish. BGA gives off BMAA, a neurotoxin strongly associated with dementia caused by brain plaques in mammals. That includes humans.

I'll link to a recent article about research on the subject. Best advice: treat BGA aggressively & early, don't eat fish from a lake with BGA, and don't swim or wade in it.

By the way, if someone is exposed to BGA, they might consider L-serine supplements. Cheap insurance.

https://www.washingtonpost.com/local/soc...a902_story.html

BGA is harvested in Klamath Lake and sold as a dietary supplement.

That author of the Washington post article does a disservice to the public. 1. She does not identify any specie of bluegreen algae (Cyanobacteria) and lumps all bluegreen algae as toxic.
This is basically the same as saying a person was bit by a snake and he died of snake venom. So all snakes are poisonous.

Anybody have any experience with or new information on Phoslock for Phosphorous control in the last 3 years?

Cody note - yes, I agree. It would be very good to get some testimony about Phoslock.

Rex performed alum, lime, and copper sulfate treatment at my place in 2017. Was very successful. I feel like my pond gained 5+ years of water quality youth.

We have done a number of phoslock applications over the last four years. Alot of discussion about alum but in our area (coastal SC) our waters are soft and alum is usually not a candidate. In one case we had a 2 acre lagoon 15+ years old, routine HAB boom and bust blooms and finally a fish kill (even with aeration). After testing phosphorous levels we did a complete reset, or attempted to remove all the phosphorous. We've had no HABs or treated algae in 4 years. Note this was not managed for fish but for aesthetics. Have also done partial phosphorous removal to reduce fertility. Yes phoslock is expensive but it works. Invest in proper water chemistry tests.

I'd like to throw some info in on this as Phoslock is one of the products I looked at when I started my research. I have the MSDS sheet for this product which until recently, was available to view, now it just says "proprietary" ingredients.
The reason this product doesn't work well in soft water conditions is because the buffering agent is Sodium Carbonate-zero effect on hardness because it has zero Calcium.
Thanks to Rainman, (Rex), I researched this until my eyes wouldn't work. I dug hard because Rex said to use Hydrated Lime instead of Sodium Carbonate (soda ash). I wanted to use soda ash because we had a pallet of it. I just needed to find the answer as to why Rex said Hydrated Lime only.. The reason is the hydrated lime is loaded with calcium. Not only is it a good buffer for acidic reactions of Alum, it brings the alkalinity up (increase hardness).
Phoslock can't (won't) do that.

Anywhere Phoslock will work, Aluminum sulfate/Hydrated Lime will work, and at a fraction of the cost. Phoslock is Aluminum Sulfate and buffered with sodium carbonate to counter the acid created by the alum....It is the reaction between the Aluminum and Phosphorus that creates Aluminum Phosphate to bind and render the Phosphorus unavailable as a nutrient

I re read this and needed to correct some info here..
Wade B's comment that Phoslock "works good" there indicates that Aluminum Sulfate is just fine in soft water-That's the chemical that locks up the Phos..
Soda ash IS the buffer in Phoslock (only for pH stability-does nothing else).
Hydrated Lime is a much better Buffer for Aluminum Sulfate because it adds hardness/Calcium/minerals that the system NEEDS.
I'm 100% on board with Rainman here, just needed to clarify my statement above as the question came up about "Phoslock" in general. I have the original MSDS sheet for this product that the manufacturer no longer lists. Hope that cleared that up-pun intended.