What should my phosphate level be?

[Huro]

Hi everyone,

So I am wondering what my phosphate should level be in a planted tank, I just used the API test kit and my result was 1.0ppm. I only have three plants in the tank right now but I am just trying to get an idea of what I should be looking for right now and when the tank is fully planted. Thanks

 

[Plantaholic]

2.0 is what I have read. I think either OldScales or Rivercats posted that is what they shot for...

 

[Huro]

2.0 is what I have read. I think either OldScales or Rivercats posted that is what they shot for...

Ok thanks for help

 

[Jodisgermanshepherd]

Following

 

[Sk3lly]

Phosphate level is related to nitrate level. You should be aiming for a ratio of 1:10. So if your nitrate is 10ppm, 1ppm of phosphate is fine. If your nitrate is 40ppm, you want 4ppm phosphate.

Hope this helps

 

[Huro]

Phosphate level is related to nitrate level. You should be aiming for a ratio of 1:10. So if your nitrate is 10ppm, 1ppm of phosphate is fine. If your nitrate is 40ppm, you want 4ppm phosphate.

Hope this helps

Thanks for the tip Sk3lly

 

[Rivercats]

Not all tanks run at a 1:10 ratio. Since I have tons of non-green plants in most of my tanks I run nitrate at 10ppm and phosphate from 3-5ppm. I also run a couple all green tanks and still use these amounts.

In general tanks can run from 1-5ppm (and even higher up to about 10ppm). If your tank develops any GSA then raising phosphates to 3ppm or higher will keep GSA from forming.

 

[Sk3lly]

Not all tanks run at a 1:10 ratio. Since I have tons of non-green plants in most of my tanks I run nitrate at 10ppm and phosphate from 3-5ppm. I also run a couple all green tanks and still use these amounts.

In general tanks can run from 1-5ppm (and even higher up to about 10ppm). If your tank develops any GSA then raising phosphates to 3ppm or higher will keep GSA from forming.

Thank you. Ive tried to run at the 1:10. So its pretty flexible then?

 

[Rivercats]

IMO yes, phosphate levels are flexible.

 

[BBradbury]

Hello Huro...

Phosphates should be low, but you don't need to know the exact level. You can judge the level by how much algae you have in the tank. Algae thrives in water with high phosphates. If you have a lot of algae, you have high phosphates. To maintain healthy levels, you should change half the tank water weekly in tanks 30 gallons or smaller. The tanks larger than 30 Gs can generally go 2 weeks between 50 percent water changes. Floating plants will also help maintain low phosphates. Hornwort and Anacharis are likely the best. Just drop individual stems of these plants into the tank.

You should limit the flaked foods too. Most of them contain phosphate.

B

 

[Huro]

Not all tanks run at a 1:10 ratio. Since I have tons of non-green plants in most of my tanks I run nitrate at 10ppm and phosphate from 3-5ppm. I also run a couple all green tanks and still use these amounts.

In general tanks can run from 1-5ppm (and even higher up to about 10ppm). If your tank develops any GSA then raising phosphates to 3ppm or higher will keep GSA from forming.

Thanks Rivercats!!! I was hoping you would pop into this thread with your expertise

 

[Huro]

Hello Huro...

Phosphates should be low, but you don't need to know the exact level. You can judge the level by how much algae you have in the tank. Algae thrives in water with high phosphates. If you have a lot of algae, you have high phosphates. To maintain healthy levels, you should change half the tank water weekly in tanks 30 gallons or smaller. The tanks larger than 30 Gs can generally go 2 weeks between 50 percent water changes. Floating plants will also help maintain low phosphates. Hornwort and Anacharis are likely the best. Just drop individual stems of these plants into the tank.

You should limit the flaked foods too. Most of them contain phosphate.

B

Thanks for the help BBradbury, I do not use flakes foods so that isn't an issue for me and I usually do about a 45% water change weekly when I am home.

 

[Rivercats]

Hello Huro...

Phosphates should be low, but you don't need to know the exact level. You can judge the level by how much algae you have in the tank. Algae thrives in water with high phosphates. If you have a lot of algae, you have high phosphates.

This simply isn't true. Algae is not caused from phosphate levels but from an imbalance of lighting, CO2, and ferts. People who use EI dosing often have quite high levels of nitrates and phosphates and never get a touch of algae. I've run tanks for over a year at a time with phosphate levels as high as 10ppm and never had algae issues. If you read through many planted tank threads you'll find plenty of hobbyist running higher phosphate levels and again with no algae issues. In most planted tanks the absence of algae means you have a balanced tank with proper amounts of nutrients. Knowing phosphate levels is a good thing in planted tanks the same as knowing nitrate levels. Also most high grade flake fish foods today do not contain phosphates.

 

[BBradbury]

Hello Cats...

I disagree. All plants need phosphate for growth, especially algae. Algae needs this nutrient moreso than standard aquarium plants. You don't want a tank with water phosphate free, but by limiting it you slow or stop the algae from growing. This allows the aquarium plants to use the bulk of the phosphates available, because they are a more complex plant than algae. So, the algae starves and shrinks.

I'd also disagree with importance of knowing the phosphate or nitrate levels. By removing and replacing a lot of tank water and doing it often, you don't need to test the water. The reason is simple, it takes time for wastes or anything else to build to a level that 's harmful to fish or plants. If you remove the old water often enough, there's no time for the wastes to buildup before they're removed. I haven't tested the water in my tanks in a very long time, but I'm also a water change fanatic.

I have little or no visible algae in my planted tanks, because I limit the food, phosphates. The lighting runs for 12 hours per day, there's no CO2 other than what's in the air and the ferts are provided by the fish. Pretty simple.

B

 

[Sk3lly]

Hello Cats...

I disagree. All plants need phosphate for growth, especially algae. Algae needs this nutrient moreso than standard aquarium plants. You don't want a tank with water phosphate free, but by limiting it you slow or stop the algae from growing. This allows the aquarium plants to use the bulk of the phosphates available, because they are a more complex plant than algae. So, the algae starves and shrinks.

I'd also disagree with importance of knowing the phosphate or nitrate levels. By removing and replacing a lot of tank water and doing it often, you don't need to test the water. The reason is simple, it takes time for wastes or anything else to build to a level that 's harmful to fish or plants. If you remove the old water often enough, there's no time for the wastes to buildup before they're removed. I haven't tested the water in my tanks in a very long time, but I'm also a water change fanatic.

I have little or no visible algae in my planted tanks, because I limit the food, phosphates. The lighting runs for 12 hours per day, there's no CO2 other than what's in the air and the ferts are provided by the fish. Pretty simple.

B

Are your tank low light?

 

[Rivercats]

BB you said "You can judge the level by how much algae you have in the tank. Algae thrives in water with high phosphates. If you have a lot of algae, you have high phosphates" This statement is false. High phosphates do not cause algae. It is caused from an imbalance of light, CO2, and ferts.

"You don't want a tank with water phosphate free, but by limiting it you slow or stop the algae" Again this statement is false as limiting phosphates does not slow or stop algae. All planted tanks have different requirements. Different Par levels of lighting, amount of time lighting is run, levels of CO2 in a tank whether they are the natural balance in all tank or if a tank has added CO2, and balanced micro and macro nutrients all determine algae or lack of algae. Phosphates in itself do not cause algae even in higher ppm's. It is also a fact that GSA doesn't form in higher phosphate levels.

Actually algae needs longer photoperiods before it can begin photosynthesis whereas plants (except in very low light) can begin photosynthesis in shorter photoperiods. Lighting and type of plants used also determine how much phosphates are needed in a planted tank.

You have low light, mostly no substrate tanks from the pic's you have provided in the past and you use a lot of terrestrial/bog plants and not more complicated planted tanks. You have found a balance that works in your tanks but that in no way is the way all planted tanks works. If someone has higher tank lighting, a lot of fast growing stem plants, and many other factors they usually always need to supplement phosphates thru fertilization. When using ferts testing needs to be done to monitor the amounts in your tank. Plus using higher amounts of phosphates can be beneficial and again will not cause algae in higher amounts. There are many reasons that cause algae growth and saying that just limiting phosphates will keep algae low or non existent is not true.

Knowing your nutrient levels is very beneficial whether you believe it to be or not. You have a very simple set up in your tanks and have run your tanks a long time so you can pretty much judge how your tank and levels are running. I too have a good idea of what all my tanks run at but I have learned this over time but due to the type of planted tanks I run I do test for nitrates and phosphates along with gh, kh, and ph. If not testing works for you that is perfectly fine but I do not suggest newbies (unless they have very low light and low light tolerant plants) or anyone running more complex planted tanks not to test for these levels even when doing large weekly WC's. I also do 50% WC's in all my tanks weekly including my 220g.