# Let's talk Phosphates



## BBradbury (Nov 8, 2010)

Hello nw...

The best ways I've found to control algae is have a thick growth of Anacharis floating in the tank and change out a lot of tank water every week. This does a couple of things: The Anacharis uses the added nutrients and gives off a mild toxin that retards the growth of most kinds of algae. The large, frequent water change removes excess nutrients and maintains a steady water chemistry.

B


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## klibs (May 1, 2014)

You don't just 'get algae' because you lack phosphates. Of course plants need some phosphates to grow well. How much they need depends on a LOT of factors (light, type of plant, CO2 use, etc...). This is why people dose EI - to make sure nutrient deficiencies are never an option. Generally you have too much light / not enough plants. This is the MOST COMMON cause for having algae. People spend too much time worrying about specific levels of nutrients when really their problem is much more obvious. As always - more info on your setup and pics of your tank would help diagnosis.

Here is my general 'why you probably have algae response':



klibs said:


> Here is my basic understanding after a few years of (trying) to do this stuff right.
> 
> you need to supply your tank with enough light, CO2, ferts, etc in order for plants to harness that energy and turn it into growth. Algae is an extremely simple organism and is able to utilize these sources much more easily to grow itself. However if your plants are healthy and using up all of the resources that algae would otherwise use (growing healthy and at a good rate) then algae will essentially 'lose the battle' and not show its face in your tank.
> 
> ...


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## nwcorner (Nov 20, 2014)

I am really asking because I wonder how phosphorous as a macro nutrient relates to algae growth. Because of what I read when I see pictures of river deltas. I accept algae as an aspect of my tank. Thank you for your advice. 

I must ask because I know many others who read this forum have the same question. Is the picture of you on the avatar yourself or is it Nick Cage? I feel stangely honored be your answer because it might be from a celebrity. If it's you, you are a good looking guy.

How necessary is adding phosphorus in a tank? Am I in the wrong forum to ask this? Any answers are helpful to me!


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## randym (Sep 20, 2015)

Tom Barr says phosphate doesn't cause algae. He's tested it, setting up tanks with varying levels of phosphate, including levels way higher than you would normally have. Even ridiculous amounts of phosphate don't cause algae.

IME, he is correct. I have a lot of phosphate in my water naturally. I think the water treatment plant adds it, to protect the pipes or something. There's also some in the water naturally. (The water comes from a river that gets agricultural runoff.) It doesn't cause algae problems in my tanks.

Have you tried EI or PPS dosing? If your water has no phosphate at all, it would probably help to add some.


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## Immortal1 (Feb 18, 2015)

Don't know that I can add a lot to this, but, in my case I was having a fair amount of GSA in my tanks with phosphate around 1-2ppm. I changed my fert mix so that I ended up with around 5ppm phosphate and the GSA has diminished alot! No, it is not completely gone but is also no longer an eyesore. Hope this helps.


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## WaterLife (Jul 1, 2015)

Thanks for mentioning Tom Barr's experiment with Phosphates randym.

Plants and algae do need a little phosphates which is usually present in the water.

I have heard that having higher silicates than phosphates will bring about Diatoms (brown "algae").


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## Linwood (Jun 19, 2014)

The one Algae I've heard is encouraged by low phosphates is green spot algae. I can say I had a moderate case, increased phosphates from near zero to about 2-4ppm, and almost all GSA is gone from two tanks. One experiment does not a conclusion make of course, but FWIW.


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## nwcorner (Nov 20, 2014)

FWIW; For What I Wanted? Found What I Wanted?
Is the reason agricultural runoff causes algae blooms because there is natural sunlight? And with our tanks we can limit the sunlight to less hours? There are definitely not as many plants in many natural waterways as there are in my tank...


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## Linwood (Jun 19, 2014)

Sorry, FWIW is commonly used to mean "For what it is worth" meaning I have only that data to offer.


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