Results of Phosphate test on Tetra Color Plus Tropical Flakes

[jarrod0987]

I am having a serious phosphate issue in my planted tank. Am trying to track down the source. One of the suspects was the fish food. I thought perhaps it had a phosphate preservative. There are 2 places on the ingredients that mention phosphate as part of another compound.

I left a small pinch of these flakes in dechlorinated tap water in a coffee mug to soak for a week.

I tested the levels with a Hanna ULR Phosphate Checker. That device is rated for Sea Water but I have consulted with Hanna Instruments and they have advised they do have customers that use that meter with fresh water. There other phosphate checkers work with both, and I have never seen a phosphate test that did not work with both. So I am confident this meter will be reasonable. Also...I did a 10x dilution of the sample in case the amount was very high. That will cause some error.

My findings were 21 ppb of phosphorus. Multiplied by 10x for the dilution correction is 210 ppb. Hanna states to convert phosphorus result to phosphate to Multiply by 0.003. That have 0.63 ppm of Phosphate. My tap water tests exactly the same at the time I set up the experiment.

It looks like dissolving did not extract any measurable amount of phosphate from the food. I did not notice any decomposition of the flakes. Bacterial action does not seem to have happened. I a not sure why. Had it happened there should have been some Phosphorus in the results. However, I had seen in my tank the Phosphate rise from 6ppm to 7ppm in 24 hours. It started close to 1 ppm from the tap and a week later was 6ppm. A day after that it was 7ppm. I had added 3 small pinches of flakes to help cycle which is why I was suspicious of the food but I don't really think that is where it came from now. It seems unlikely. The next suspect is the soil. Why it did not release huge amounts of Phosphate at the beginning I don't know. I scrubbed the phosphate out this past weak with GFO. It is around 0.6ppm now. I am going to discontinue the GFO and give it a week and not add any flakes. Will see what happens. There are live plants in the picture but there size did not change this week.

 

[Fresh2o]

I'm thinking you would see phosphate released from flakes after digestion from fish (and from bacteria I suppose).
What brand of soil are you using? Perhaps it takes time for the water to saturate the soil before releasing phosphate? Idk. I'm using an inert substrate (EcoComplete) so I've had to triple dose my ferts to come close to that phosphate level.
Did you try testing soil + DI water? This should parallel your tank minus the other factors.


Sent from my iPhone using Aquarium Advice

 

[jarrod0987]

I'm thinking you would see phosphate released from flakes after digestion from fish (and from bacteria I suppose).
What brand of soil are you using? Perhaps it takes time for the water to saturate the soil before releasing phosphate? Idk. I'm using an inert substrate (EcoComplete) so I've had to triple dose my ferts to come close to that phosphate level.
Did you try testing soil + DI water? This should parallel your tank minus the other factors.


Sent from my iPhone using Aquarium Advice

Doh!!! I should have tested the soil with DI water!! Thank You
Of course...It could take a while to be released from the bacteria eating the organics in the soil too but meh....Muddy DI Tea created

I am using Miracle Grow Organic Choice.

 

[Caliban07]

In natural waters phosphate is very low. In a home aquarium, it is unlikely you will ever succeed in keeping phosphates down without using a special phosphate removing media.

It comes from the addition of fish food that has been broken down by bacteria or digestion through fish. It takes a while to accumulate but fish food is constantly added.

Phosphate doesn't cause algae and I am yet to find any articles that claim high levels of phosphates suppress the uptake of other nutrients. It doesn't harm fish.

I wouldn't worry about high phosphates. Why do you want to get it down?


Sent from my iPhone using Aquarium Advice

 

[jarrod0987]

I have a lot of experience with Phosphate in Reef and fish only marine tanks I have kept in the past.

I agree, you will not control Phosphate without media such as GFO or also I have been experimenting with Lanthanum Chloride. It worked in the aquarium but mysteriously not on the tap water I make water changes with.

I do not agree that limiting phosphate does not control algae. I have had great luck preventing and removing green algae both cyano and Green hair by keeping Phosphate down in the parts per billion. This is well known in the salt water side of the hobby and lot's of well established reef keepers agree and use these methods every day.

That is why I want to control them. It has nothing to do with nutrient uptake.
Obviously I need to keep a little for the plants. I had 7ppm for a day there. Got it down to 0.6ppm with GFO which is much more acceptable.

You may want to look into the Redfield Ratio. It refers to plankton in the ocean and growth of Cyano and GHA but it has also been shown to effect freshwater systems in a similar way.

Here is a page that refers to freshwater.
http://buddendo.home.xs4all.nl/aquarium/redfield_eng.htm

 

[gemach7]

More plants will help control phosphate. Removing entirely in freshwater will negatively effect plant growth. As a guide the shallower the roots and more plant above the substrate the more phosphorus is required by said plant. With the exception of mangroves saltwater macro algae does not have the same requirements for this chemical, and also where high concentrations can negatively effect the growth of some corals. If your seeing phosphate levels rise I would add more broad leafy plants. They use this chemical during growth and reproduction.
In non planted aquariums the phosphate level is normally controlled by PWCs or media.


Sent from my iPhone using Aquarium Advice

 

[Caliban07]

I do not agree that limiting phosphate does not control algae. I have had great luck preventing and removing green algae both cyano and Green hair by keeping Phosphate down in the parts per billion. This is well known in the salt water side of the hobby and lot's of well established reef keepers agree and use these methods every day.

That is why I want to control them.

Hmmm I dunno. Dr Walstad runs her planted tanks with phosphates as high as 5ppm + she claims here tanks are algae free.

My tank has something similar, could be 10 + but can't tell as the colours are so similar. If excess P played such a big role in the formation of algae I would expect my tank and Dr Walstad's tanks to be overrun. Alas, they are not.




Sent from my iPhone using Aquarium Advice

 

[Fresh2o]

More plants will help control phosphate. Removing entirely in freshwater will negatively effect plant growth. As a guide the shallower the roots and more plant above the substrate the more phosphorus is required by said plant. With the exception of mangroves saltwater macro algae does not have the same requirements for this chemical, and also where high concentrations can negatively effect the growth of some corals. If your seeing phosphate levels rise I would add more broad leafy plants. They use this chemical during growth and reproduction.
In non planted aquariums the phosphate level is normally controlled by PWCs or media.


Sent from my iPhone using Aquarium Advice

+1,000,000
The rules are different with planted tanks
OP - How heavily planted is your planted tank? What lighting are you using? Both will factor heavily in phosphate uptake.


Sent from my iPhone using Aquarium Advice

 

[jarrod0987]

More plants will help control phosphate. Removing entirely in freshwater will negatively effect plant growth. As a guide the shallower the roots and more plant above the substrate the more phosphorus is required by said plant. With the exception of mangroves saltwater macro algae does not have the same requirements for this chemical, and also where high concentrations can negatively effect the growth of some corals. If your seeing phosphate levels rise I would add more broad leafy plants. They use this chemical during growth and reproduction.
In non planted aquariums the phosphate level is normally controlled by PWCs or media.


Sent from my iPhone using Aquarium Advice

Yes I understand the specs are different. In freshwater I have heard everything from a 5 to 1 ratio to a 16 to 1 ratio. If P is high then N would have to be massive. SO I like to keep my under 1ppm. If plants look bad I can always let it rise a bit.

 

[jarrod0987]

Hmmm I dunno. Dr Walstad runs her planted tanks with phosphates as high as 5ppm + she claims here tanks are algae free.

My tank has something similar, could be 10 + but can't tell as the colours are so similar. If excess P played such a big role in the formation of algae I would expect my tank and Dr Walstad's tanks to be overrun. Alas, they are not.




Sent from my iPhone using Aquarium Advice

I like her a lot. I read her book but I have to read it a few more times She does talk about how allelopathy can keep algae out sometimes as well. I thought I read in there both N and P test for 0ppm because her plants eat it so fast. I will look again. Thanks for pointing that out

 

[jarrod0987]

+1,000,000
The rules are different with planted tanks
OP - How heavily planted is your planted tank? What lighting are you using? Both will factor heavily in phosphate uptake.


Sent from my iPhone using Aquarium Advice

I have about 20 plants of various species. 2 are AS's. I am testing one of those new plant capable LED fixture from Current USA. I agree the rules are different with plants. I'm pretty sure that 7ppm phosphate is not one of them That's what I had. I am going for N between 1-2ppm and P <1ppm right now just to see what happens
I planned on doing this as a low tech tank with dirt but I think these LED fixtures put off a lot more par so probably it's a high light situation. ALl my plants look decent except the swords. I'm trying to get to the bottom of that right now. I will get some pics for you guys as soon as I get this news DSLR camera figured out.

 

[Fresh2o]

Regarding PAR levels, it depends on which Current Satellite model you are using. At 12", PAR values are 15+, 35+, and 100+ for the LED, LED+, and LED+ PRO, (Low, Low-Med, High) respectively. If you are running the LED (not +), then the phosphate demand will be minimal.
Swords are heavy root feeders. Since your swords are planted in soil, lack of substrate nutrients should not be the culprit.



Sent from my iPhone using Aquarium Advice

 

[jarrod0987]

I have Satellite Plus. Water depth from surface to top of substrate is 8.5" I see you listed 3 values of par for each fixture but I'm not sure what scenario they use. I just hit the full spectrum button. Seems the whites and RGB's are on all the way?

 

[Fresh2o]

The specs did not indicate the light settings.
At 8.5" depth you should be in the middle of medium light and capable of growing most plants.


Sent from my iPhone using Aquarium Advice

 

[jarrod0987]

I understand what you meant now. I was more worried I might be over driving the plants with too much par and causing a Carbon shortage. I don't think so because the plants structure is intact and not melting. Something is wrong with the chlorophyll in the swords but I have N P and Mg. I am zeroing in on Iron. Even the Seachem Fresh or salt water low range Iron Multi test came back 0 after 45 minutes of waiting for chealated Iron to appear. Iron is important for synthesis of chlorophyll. Thanks for the par on the light fixture. I have an Apogee par meter but it doesn't work for LED which is all I use these days

 

[Caliban07]

Here is a snippet from here book that describes what I was saying.



Also I was going to mention iron. There are about 4 pages in iron and algae.



And you Also are very right about allelopathy. All the plants needs need to be met for this though.

Here is a question from a letter that was sent in and her response.



There is a full chapter on algae control and s full chapter on allelopathy too.

Although the book is based on one particular method the science behind the plants in general is the same and she addresses a lot! Definitely worth a read if you have any kind of planted tank set up



Sent from my iPhone using Aquarium Advice

 

[jarrod0987]

Here is a snippet from here book that describes what I was saying.

View attachment 276270

Also I was going to mention iron. There are about 4 pages in iron and algae.

View attachment 276272

And you Also are very right about allelopathy. All the plants needs need to be met for this though.View attachment 276273

Here is a question from a letter that was sent in and her response.

View attachment 276271

There is a full chapter on algae control and s full chapter on allelopathy too.

Although the book is based on one particular method the science behind the plants in general is the same and she addresses a lot! Definitely worth a read if you have any kind of planted tank set up



Sent from my iPhone using Aquarium Advice

Thanks for all the pics I own the book I read it cover to cover but so much to take in I have to go through it a few more times to soak it all in. I can only absorb Ferrous information not ferric information I get a lot of what she is saying but some of the Iron stuff is pretty tough for me

 

[jarrod0987]

Ok so to test Fresh2o's Idea that I should have thought of. I soaked a few spoons of that soil from the original bag in DI water for 24 hours. Tested for phosphate and it was off the chart. That's defiantly where it came from. I guess the reason I did not suspect it is because after 24 hours of starting the tank Phosphate was only 2 ppm which was exactly what my tap water was testing for when I filled it. I guess it just took time for the water to soak down into the gravel and then into the soil and all that Phosphate to come out with osmosis as there is no flow so deep in the gravel. I will have to watch it for a while and see if it will behave. I don't have much N right now so I don't need any Cyano outbreaks.