dried seaweed (nori) and water quality

[StrategicReef]

Wouldn't nori be packed with phosphates since they are a plant that exports them from the ocean?
Are they as bad for water quality as meaty foods? How to judge how much to feed nori?

 

[Randy Holmes-Farley]

Nori has phosphate like any food does, but not grossly more relative to the protein content.


Ron Shimek analyzes some foods here;

http://web.archive.org/web/20010720071031/http://www.animalnetwork.com/fish/data/foods.asp

I calculate the phosphate to protein ratios to be:


Formula Two...........................176
Formula One.............................69
Frozen Brine Shrimp................232
Frozen Plankton/Krill...............182
Golden Pearls..........................273
Lancefish.................................244
Nori..........................................221
Plankton Gold Flakes...............169
Prime Reef.................................69
Saltwater Staple......................500
Silversides...............................952
Tahitian Blend..........................318

 

[Tuscaquatics]

I have to say that when I had a tang and I fed him nori everyday, I watched my nitrates and phosphates become a problem pretty quick. I would recommend using the stuff sparingly.

 

[cthetoy]

Nori has phosphate like any food does, but not grossly more relative to the protein content.

http://web.archive.org/web/200107200...data/foods.asp

Randy. The link is not working

 

[bertoni]

Link fixed.

 

[doryrocks]

they're only a problem if they are not eaten, so feeding them sparingly is a good idea.

 

[Randy Holmes-Farley]

Why do you think it different if eaten or not?

Most vertebrates excrete much of the nitrogen and phosphorus they consume, especially adults, which excrete basically all of it.

 

[rayjay]

I don't know why flake food/plant food gets such a negative reaction for phosphates all the time.
Has anyone done tests on frozen foods or pelleted foods?
I have and it's amazing how much phosphate is present in any food I've tested.

 

[Randy Holmes-Farley]

Phosphate is sometimes added to fresh, frozen and canned seafood to keep it hydrated, and so if a manufacturer (or aquarist) uses such a source, the levels may be unusually high.

Also, anything with bones in it will be super high in phosphate. Fish meal, for example, might be an ingredient to avoid in foods (it is present in some flake foods).


I mention it here:

Phosphate and the Reef Aquarium
http://reefkeeping.com/issues/2006-09/rhf/index.php

from it:

Flake fish food is typically about 1% phosphorus (3% phosphate equivalent) by weight (and many products have such phosphorus data on their labels). Consequently, if five grams of flake food is added to a 100-gallon aquarium, there is the potential for the inorganic orthophosphate level to be raised by 0.4 ppm in that SINGLE FEEDING! That fact can be a significant issue for reefkeepers: what do we do with all of that phosphorus? If the food is completely converted into tissue mass, then there will be no excess phosphate. But much of the food that any heterotrophic organism consumes goes to provide energy, leaving a residue of CO2 (carbon dioxide), phosphate and a variety of nitrogen-containing compounds (ammonia, nitrite, nitrate, etc.) as shown above. A fish, whether it is an adult or a growing juvenile, consequently excretes much of the phosphorus that it takes in with its food as phosphate in its waste. Of course, overfeeding will result in more phosphate delivery than will reduced feeding levels.

 

[rayjay]

Is the phosphorus naturally in foods found in terms of phosphates or is it in a form we don't have to worry about.
In checking the USDA nutrient data charts, (raw, unprepared, untreated foods) the kelp, spirulina and other marine plant food contain very little natural phosphorus compared to things like the various fish, crab, shrimp etc, which are are usually over 200mg/100g phosphorus which would be over .2% phosphorus without any preservative added.
If that phosphorus is in the form of phosphates that affect the tank, then the level of phosphate would be a lot higher percentage than the phosphorus.
If this is the case, I would rather add spirulina or nori or kelp to my tank than the "meaty" foods.

 

[schnitm]

Almost all phosphorus in living tissue (plant or animal) could end up as phosphate in reef tank water. Except for the small fraction bound to iron or lanthanum or somehting else that keeps the phosphorus at reef tank PH levels, it's all available for growth or to become phosphate in the water.

In the kidney world in humans we have a somewhat lower fraction of ingested phosphate to worry about because calcium binds to phosphate in the intestines and passes. In the reef tank, calcium phosphate will ultimately release the phosphate and the calcium will become (mostly) calcium carbonate.

Giving foods to your tank that most support growth in the living things you want to grow, whatever those are, seems like a good idea to me.

 

[Chris27]

I have to say that when I had a tang and I fed him nori everyday, I watched my nitrates and phosphates become a problem pretty quick. I would recommend using the stuff sparingly.

Depending on the particular species of tang, Nori is the absolute best food you can feed them. Most tangs are almost 100% herbivorous and require large amounts of algae to thrive. My Yellow and Sailfin for example, get very thin, very quickly when I don't feed Nori daily along with two regular feedings of frozen meaty preparations. Other tangs like the Hippo's or Clowns prefer more frozen, but they still attack the Nori like it's going out of style.

Great water parameters are something we all like to have, but I feel that we should provide proper nutrition to our livestock, vice starving them for the sake of saving a couple of bucks on a protein skimmer or salt mix for frequent water changes.

 

[Randy Holmes-Farley]

Is the phosphorus naturally in foods found in terms of phosphates or is it in a form we don't have to worry about.

As schnitm mentions, nearly all of it is metabolized to and eventually excreted as inorganic phosphate. A growing organism will take up a little for its own tissue growth, but adults excrete nearly all of it.

If this is the case, I would rather add spirulina or nori or kelp to my tank than the "meaty" foods.


If you look at my table above, nori is no less phosphorus-containing per unit of protein.

 

[StrategicReef]

Well, if the nori is not that much less pollution then the meat.. how much should I feed the tang anyway, it's hard to gauge the amount because it doesn't come in cubes.

If a tang prefer meat and go crazy with the meaty food, does that mean it is bad for the tang? Protein is protein right? Yeah, I suppose seaweed have more vitaman and greenie goodie stuff



I was also concerned that the shreds of nori flying everywhere, it seems doesn't matter since you guys say it is eaten or not, the nutrient is still there.

 

[Chris27]

You can cut down on the shreds by cutting the nori into thin strips about 1/8" wide and sandwiching them into an algae clip. This way, the fish only gets a thin strip to eat and the rest stays in the clip.

 

[Randy Holmes-Farley]

The amount to feed will obviously depends on many factors, but I feed my tank one full sheet daily. It is mostly eaten by a hippo tang and a long horn cowfish.

 

[rayjay]

If you look at my table above, nori is no less phosphorus-containing per unit of protein.

Guess it's good that I use spirulina instead then.
Source: USDA nutrient chart.
100g dried spirulina contain 57.47g protein and 118mg of phosphorus.
However, taking into account the dry weight of the meaty foods, the protein content is much higher.
Guess it's best to feed some of both.

 

[Randy Holmes-Farley]

Do you know if it is from a fesh water source? I'd usually prefer a marine food.

 

[Randy Holmes-Farley]

FWIW, this site:

http://www.liferesearchuniversal.com/spirulina2.html

says spirulina contains 80 mg P per 10 g of solid, or 8,000 ppm.

So the ratio as I calculated above is 8,000 ppm/55% protein = 145, which is in line with several of the other foods above.

 

[rayjay]

Thanks for all the info Randy.
I have 3 sources of spirulina but only one, the powder from Brine Shrimp Direct that I feed my brine shrimp (that I feed my seahorses and other fish) mentions anything about source. They say that it comes from the waters of Hawaii.
Jehmco and Aqua Select don't say anything at all of the source.
After checking out your link it poses the question "Who is right, the USDA information or the Life Research Universal?
There are big differences between them.
This didn't scan too well and is small print, hard for my eyes, but here is the USDA info.
USDA nutrients for Spirulina