nori, seaweed FYI

[toothman]

I have become consumed with keeping my phosphate low in my SPS tank and looking for low phosphate foods. I thought there might be foods that did not follow the redfield ratio and have nutrients for tangs etc. I was really excited when realizing how eagerly my tangs including my finicky achilles tang consumed it. Reading the nutritional information on the rods nori pack it was interesting that it had so much protein in it and seemed like the great fix to feed my fish. I was wrong.

Checking my phosphate in the morning it was .04 so I decided not to feed anything but 2 sheets of nori today. Checking again in the afternoon the phosphate was .07. So I decided to add a 1/8 inch square piece into the hanna test vial. I shook it up and retested it Wow! .83.

I realize this was not a real controlled and exact test but I can definitely conclude that there is a lot of phosphate in nori. Not really sure if there is more than shrimp etc.

 

[gchaney]

I tend to start to get a pretty bad algae issue when using any of the RODs line I have come to the conclusion its not all its hailed as

 

[dvanacker]

Of course there is phosphates...it is an algae, but a healthy one.

 

[toothman]

dvanacker that is interesting. I did think there would be some phosphate but I also thought there would be a lot less than meaty foods. I have heard there is inorganic phosphate, I thought that is what hanna basically tested for, and there was organic phosphate. I was not aware how the two differed in the effect on marine tanks. I have read a few articles on phosphate and was spinning after reading, so complicated.

Is this good phosphate readily used by acropora.

 

[dvanacker]

Well I said the algae was good....as in Nori is a healthy food for tank inhabitants but the excess phosphates can be a problem.

Just like quality food in general can be good for the tank but you need to have a way to remove the organic waste before it is converted to NO3 and PO4 (skimmer) and you may also need a better way to deal with the broken down NO3 and PO4 (Biopellets, GFO, waterchanges).

 

[this is me]

hmmm...0.04 to 0.07 is totally within the tolerance of my Hanna meter(+/-0.04 to be exact).
Drop any food in the tester and you'll read high phosphate. I wouldn't stress it but of course, you do have to watch what you throw in the tank.

 

[aleggett321]

you took the piece of nori out of the vial before running it through thr checker, right?

 

[grcforce327]

I feed it regularly. Tested yesterday @ .036

 

[toothman]

grcforce327 curious what test you use for phosphate my hanna only has 2 significant digits. Is that a hach?

 

[grcforce327]

grcforce327 curious what test you use for phosphate my hanna only has 2 significant digits. Is that a hach?

Hanna Phosphorous at 12,then do the math! 12 x 3.066/1000 = .036792

This was with nori in tank and in fuge for a bullied tang!

 

[tomservo]

I'm not sure what the problem is? If you do the math, assuming the hanna checker is a 5ml sample size, a 1/8" piece (I converted to metric - 3.175mm x 3.175mm) in that size sample is equivalent to putting 3.06 square meters of nori in your tank! Those must be some hungry tangs! What is that, like half a pound of nori? edit: That was assuming 400 gallon system volume, I see now you have a 300 gallon sump as well.. More like 5 square meters?

 

[toothman]

No problem at all, I really did not think nori had much phosphate in at all. With one sheet it did make my tank go from .04 to .07. in a 700 gallon system I was just surprised and wanted others to know that it had more phosphate in it than I would think. As mentioned it was not a scientific test, just a test to see if there was much phos in nori. In the spirit of sharing knowledge with others, sorry you did not appreciate the tip and nice to see you can do the math to calculate how many square meters it would take.

 

[tmulrney]

No problem at all, I really did not think nori had much phosphate in at all. With one sheet it did make my tank go from .04 to .07. in a 700 gallon system I was just surprised and wanted others to know that it had more phosphate in it than I would think. As mentioned it was not a scientific test, just a test to see if there was much phos in nori. In the spirit of sharing knowledge with others, sorry you did not appreciate the tip and nice to see you can do the math to calculate how many square meters it would take.

Interesting post. I fought red slime for quite some time. Finally got nutrients under control. I have a few gangs and feed half a sheet of nori per day and every single time I drop it in the tank I wonder if this could be my phosphate source. I'm going to research it more. Thanks for the post.

 

[tomservo]

Looks like .03 ppm in 700 gallons is 0.07970956g (.08g) - given a standard sheet of nori weighs 3g (wikipedia, 7x8" sheet), it's not unreasonable.

Wiki says that there is .7g of phosphorous in 100g of nori. If you feed 2 sheets (6g) and they're maybe a bit on the high side of P, I'd say it's right on.. I have always wondered how long nutrient export takes, especially at very low concentrations. Was it back down to .04 the next morning? Is your nutrient export just the fuge?

 

[klepto]

I found this article helpful with phosphate questions.
http://www.advancedaquarist.com/2012/3/chemistry

He lists nori on the chart.. it has a high phosphate content in relation to protein. I feel that removing the leftover nori before it degrades is key. Also, I think that the balanced mineral and nutrient content of raw seaweeds make them a great option for the diet of herbivorous/omnivorous fishes.

 

[Reef Bass]

Merry xmas Jake.

+1 for the nutritional aspect of nori for those things that eat it outweighing its phosphorus content.

Part of the definition of life on our planet is that it is composed of 6 elements (carbon, nitrogen, hydrogen, oxygen, sulfur and phosphorus). Thus any foods derived from living things contains at least some phosphorus.