PO4 in frozen food

[wsurf4me]

After posting this in my local forum I thought it would be a better topic here. I'm sure it's been done before but I did a little test on some frozen mysis I regularly use. I took 1 liter of water that tested 0.00 on my Hanna meter and added 1 cube of mysis to it and allowed it to thaw for 1/2 hour. I then took another sample of the water and tested it - turned blue and off the charts at 2.73!

I guesstimate I have 90 gallons of water in my system -
90 gal = 340 liters.

I normally feed 3 cubes a day -
2.73 * 3 = 8.19.

8.19/340 = 0.024.

So by my crude calculation if I don't rinse the food I'm adding 0.024 ppm? of PO4 a day to my tank, is my thinking correct here?

Took the same food and rinsed it under tap water for about 30 seconds, then rinsed with 5 liters of 0.00 water. Tested again and it came in at 0.24.

0.24/340 = 0.0007.

Much better, if you didn't already know I guess the moral of the story is rinse your food. Of course there are ways to remove the PO4 but why add it in the first place? Can anybody really say if the corals benefit from any PO4?

 

[bertoni]

Phosphorus is a macronutrient, and all organisms require it to survive and grow. The liquid around some frozen food products can contain a lot of phosphate in the dissolved form, which can be used directly by corals with photosynthetic symbionts, but also by cyanobacteria and algae. I never bothered rinsing frozen foods, but I always kept a fairly low stocking level and would never feed anywhere nearly that amount per gallon. In your tank, rinsing might be useful. The math seems about right to me.

 

[sedor]

Wow I have seen peoples studies similar to this one, but it always surprises me how much can actually be added to the system in just one feeding. Considering we strive to maintain a PO4 level of about .04. Now granted a lot of that gets removed from the system daily, but it still doesn't help if nutrients or something your battling in the first place.

 

[falconut]

I didn't realize it was that bad. I feed a cube a day and don't rinse it. I'm also fighting an algae outbreak, so I supose I'll start rinsing it.

How exactly is the best way to do it? Thaw it out, then pour through a fine mesh net and rinse while it's in the net. Then mix with tank water and serve. Sound about right?

Thanks for the idea.

 

[TripleT]

How exactly is the best way to do it? Thaw it out, then pour through a fine mesh net and rinse while it's in the net. Then mix with tank water and serve. Sound about right?

That's my routine. Sometimes I thaw 3-4 different cubes at once, rinse, and put in a shot glass with supplements (Zoe/Zoecon). This lasts for a few days, covered, in my fridge.

Sometimes I'll also add PE mysis, and freeze dried brine or krill. The freeze dried stuff is a supplement sponge.