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Korallin PO4 Minus

Korallin PO4 Minus


Item #: KL5111

In Stock

Together with a Protein Skimmer, this product provides an efficient export & dramatic reduction of Phosphate (PO4) in marine fish & reef aquariums. Much easier to use and way more efficient than any PO4-absorbing sponge, media, or freeze-dried bacterial product. It simply converts your protein skimmer into a "PO4 Exporter"!

Even minute level of PO4 can be responsible for unwanted hairy & red cyanobacterial algae growth, as well as the presence of "foamy" water. See the dramatic increase of PO4-saturated skimmate being pumped out from your protein skimmer before your very eyes! And verify the result with any PO4 test kit.

Under the most optimum condition, PO4-Minus brings down your system`s PO4 level from as high as 3 ppm down to 0.5 ppm in 24 hours. Depending on the water chemistry and starting level of PO4, a slower response time—which is about 0.04ppm of PO4-drop/usage of PO4-MinusTM should be expected. Its de-phosphate effect is not as gradual as AZ-NO3TM``s de-nitrate effect, expect an abrupt drop (ie: Near zero) in PO4 on around the 4th–5th day. Best to be used with the Korallin S-Plus Trace Elements to maintain a healthy kH.

Extensive testing indicates that it can be used with the AZ-NO3TM as well with no loss in potency in either product! They are best to be used together if you want an extremely low NO3 and PO4 marine environment. This product has been overdosed 10 times in our aquaria for many occasions to show its harmlessness to reef animals. Most of its users in Germany use this product once per week to control the PO4 in their fish-mainly aquaria which require constant and large amount of feeding. 500 mL & 5 L.

Shake well before use. 2–5ml for every 100 litres. Test water for PO4 after 24 hours of treatment. Repeat if necessary. Water may be cloudy for a short time. Watch kH & ORP closely. kH cannot fall below 5. If it does, use Korallin S-Plus Trace Elements, or other kH Buffers.

Manufacturer information

Korallin is a German based company who is a manufacturer of specialized aquatic components and accessories for the advanced marine aquarist.

4 Stars


Reviewed on
February 07, 2017

No, I would not recommend this.

Good por Po4, bad for tang

Pros: Good for po4 control

Cons: It kill tangs (other fishes are ok)

Is really good taking down Po4, but it kill one yellow tang. After 5ml dosing in a 70g tank. The efect was : 5 minutes later tang was breething fast, 30 minutes was in the sand, 2 hours RIP. The tang was in perfect conditions prior that.

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david brown

Reviewed on
October 31, 2011

Yes, I would recommend this.

Works Great!

It's simply lanthanum chloride which precipitates phosphate out as lanthanum phosphate. It causes cloudiness in the main tank because LaPO4 is not soluble. It's ability to precipitate phosphate from the tank water is amazing, but it only does so down to a concentration of about 0.1ppm and after that it is useless. Its great after something dies in the tank or you have fed heavily (both causing high amounts of phosphate), but if you are trying to get that last bit of phosphate down to 0ppm then forget it and just use some GFO. I dose it in my overflow so that the precipitate flows through my filter sock and into the skimmer chamber. More of the precipitate is removed this way and less ends up in the main tank to get stuck on the live rock and collect there. Use it as a tool, like anything else, and don't forget it doesn't replace regular water changes!

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Reviewed on
November 07, 2010

Yes, I would recommend this.

It works

I use this and ANO NO3 everyday, It works good (I know I over feed my tank but I just don't want anyone going hungry) My water does cloud for a few hrs after use so I do it at nite before bed. Fishes and inverts seem healthy and happy. Less algae problems.

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fish lover

Reviewed on
December 17, 2009

No, I would not recommend this.


I used 2 bottles for oven a month in my 250 gal fish tank and it brought down the PO4 from 4 mg to around 2mg (I also used AZ NO3 to remove NO3 the same time). I also continued to do the 20% water change every 2~3 weeks. With this price and cloudiness side effect, I might as well change the water which will give the similar result without the side effect.

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al medina

Reviewed on
June 26, 2009

Yes, I would recommend this.

Great product!!!

For several months I had an uncontrollable outgrowth of brown slime algae/diatoms in my reef tank. Tried different products and filtration devices plus water changes & purchasing more snail/crabs with little change. The water seemed yellowish and turbid. As soon as I added Korallin PO4 my skimmer went wild and the algae bloom ceased in about 3-4 days. My tank is crystal clear now and all the inhabitants including my green carpet anemone are happy!

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matthew gay

Reviewed on
April 07, 2009

Yes, I would recommend this.

Did Not Perform as Expected

I used this product for approximately 3 weeks, until I used it all. It took a starting phosphate level of 1.0 to 0.5 in a 3 week period in mt 75 gallon tank. I was expecting it to get the level down to 0. It did not cause any adverse events and it did work some but not to my expectations.

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Reviewed on
December 01, 2008

Yes, I would recommend this.

PO4 minus works

I have used this product over and over and I will continue to use. Removes PO4 everytime -- all you need to do is clean out the protein skimmer regularly after you have added - usually the next day you will see a significant amount removed from your tank - THis product works better than my PO4 reactor and is easier to deal with

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anthony vitale

Reviewed on
January 08, 2008

Yes, I would recommend this.

reitre your reactor

more cost effective than rowa works faster tank looks cleaner quicker 0 micro algae on glass,unlike iron based products no running 6 to 8 gallons of water through reactor for rowa most important,animals look great using A&E reef devil deluxe on a 75 reef, no side effects with this great skimmer. thanks korallin. affects on this great skimmer

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ronald rush

Reviewed on
April 12, 2007

Yes, I would recommend this.


Within 4 days my PO4 went from 1.0+ to 0.25. Almost too quick, but I backed off the recommended dosage and slowed it down, and from there I got it to around 0+ in about a weeks time. Definately gives a richer skimmate. It didn't affect my PH or KH either. Remember, go slow if you have corals and inverts. I'd go with the 3 mil per 25 gal for the first 2 days, then down to 2 mil per 25 from there. Overall my tank looks cleaner, and the animals seem the better for it.

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andy schack

Reviewed on
January 12, 2007

Yes, I would recommend this.

Great Product

Wanted something easier to use to control PO4 in my tank and something I could use on a regular basis. This stuff works great and I observed no adverse effects. Worth a try. I now use all Korallins products.

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