Rinsing Frozen Brine Shrimp?

[Randy Holmes-Farley]

I wonder about the tiny bits of brine shrimp, mysis or whatever that get rinsed down the drain instead of entering the water column uneaten and then breakdown. If there’s phosphate locked up in the “bits” that is released when they breakdown as uneaten food, then rinsing is worth it for me. On a mature reef probably doesn’t make a difference as there’s plenty inhabitants to take up the “bits”

That thought may reflect a misunderstanding of what actually happens when something is "eaten".

If a fish eats a chunk of food, nearly all of the phosphate in it is released back to the water. It is not retained in the fish. For an adult fish that is not rapidly increasing in size, essentially 100% of the N and P eaten is released back to the water. The same happens in all organisms, including people. A juvenile fish that is growing will take up a fraction of the N and P it eats and make it parts of its own tissues, but much less than half is retained.

If organic compounds enter "the water column uneaten and then breakdown. ", the net process is not a whole lot different. Bacteria will retain a fraction of what they ate, and release the remainder.

In general, it makes little to no difference to the ultimate accumulation of nitrate and phosphate in the water whether a chunk of food is eaten by a fish, or it just "rots" on the bottom of the tank. nearly all of the N and P ends up in the water in either case.

This is a very important aspect of nutrient cycling that I tried to convey in the above-mentioned article that most people didn't not previously think through with comments such as the "benefit" of rinsing food, making sure it is all eaten, etc.

 

[ReefHog]

After reading what Randy is saying I feel enlightened. I'm not a chemist but it makes since to me. But in, say, a sparsely populated reef wouldn't a good portion of the uneaten bits of food find a way into the rock work and break down? In that case it's not the difference between the food being eaten by fish or not. It's the difference of the food bits making it into the aquarium or not. And in an aquarium that might be having some algae issues already, wouldn't it be better to just rinse the food?

 

[ALRUI]

After reading what Randy is saying I feel enlightened. I'm not a chemist but it makes since to me. But in, say, a sparsely populated reef wouldn't a good portion of the uneaten bits of food find a way into the rock work and break down? In that case it's not the difference between the food being eaten by fish or not. It's the difference of the food bits making it into the aquarium or not. And in an aquarium that might be having some algae issues already, wouldn't it be better to just rinse the food?

I'm leaning towards rinsing at this point just as a preventative measure as the frozen brine I got at my small rural pet shop is likely low quality anyway.

 

[graffitireef]

I always found rinsing to be counter intuitive to the food I was using because it was filled with a plethora of small stuff to feed corals and filter feeders in my tank. Most food packagers already rinse their stuff anyways. Whatever isnt used by your tank should just end up like all the other waste in your tank.

 

[Susan Edwards]

Interesting. I use a strainer for copepods, very fine. I just set it in a bowl of ro water, thaw, lift strainer out (got it at the brine shrimp direct site in different mesh sizes) and dump into jar. But now, maybe I won't rinse. Had thought not rinsing contributed to my bryopsis issue last year. I also read that the liquid is beneficial to corals and filter feeders but was afraid of the return of algae.

 

[JoeyDiesel]

IMO, one of the potential contributing factors to depleting potassium is rinsing frozen foods, washing away the potassium. Normally, potassium is loose inside cells, held inside by the cell membrane.

Freezing tends to damage cell membranes by ice crystals distorting them. That can lead to release of ions inside of cells, and rinsing would then wash away the potassium.

If you then use the remaining organics to regenerate new tissues (corals, fish cells, etc.) then more potassium must be sucked up to fill in the new cells.

Membrane leakage of solutes after thermal shock or freezing
https://www.sciencedirect.com/science/article/pii/0011224073900187
"There was extensive loss of cell potassium and uptake of sodium at all cooling rates, the cation concentrations across the cell membrane approaching unity."

This makes a lot of sense, ever since I started rinsing food so religiously I've been struggling to keep up with potassium.
I will be putting this to the test!

 

[Dennco2000]

Omg, thank you for posting "Rinsing does virtually nothing. Dr. Randy wrote a paper on this" This whole rinsing and garlic yada yada yada! just stop it!
I have a a large diversity of fish here is feeding technique: Every 3 days I put mysis and brine cubes in a ketchup dispenser add tank water. Morning I give a shot to the tank then a 3X3 sheet of nori. Later aka dinner another sheet of nori. Then twice a week in the evening Hokari marine - s pellets. This will cover 90% of all tanks feeding requirements you guys micromanaging your fish fish are setting yourselves up for disaster. Just don't slack up on the water test.
My 2 cents..... garlic? paleeese.