I Keep Reading That People Are Washing Frozen Food Before Feeding.. Why?

[stanlalee]

I cant possibly rinse the small amount of food I grade off a cube for the two little fish I have and I am not melting down a whole cube in hopes of reduced phophates. there is probably one drop of water in the amount of food I grade off. that being said I have never done it and never had a phosphate issue. I guess its something I'd consider if I were using a whole cube or even a quarter of one for that matter.

all that being said I dont know why gelatin and preservative free frozen food would have excessive phosphates (say a package labelled 100% krill or mussells ect). dont they just catch it, cube it and free it? from my understanding all food or organic sources are going to have some phosphates but flake food is the main offender in regards to excessive phosphates.

[widmer]

Rinsing frozen food with RO to me is the same thing as how my significant other insists on putting my letter opener in a box on the shelf rather than letting it sit out on the desk - it totally removes that whole convenience factor.

I have never rinsed frozen food, and have zero problems with nuissance algae. Granted, when I first switched from flake to frozen I had a cyano explosion, but the system eventually shifted to handle the extra nutrients and I've had zero trouble since.

Meanwhile, my tank is a 15 gallon no sump no filter no skimmer and not rinsing frozen food is causing me ZERO problems. Corals are super healthy.

[greenbean36191]

I've seen a few studies that suggest that phosphorus in food is and important aspect of fish health and growth. I believe many fish meals, which are often used as a base to make flake and pellet foods, have this phosphorus added on purpose, or at least isn't avoided as an addition.

Of course P is a required nutrient, but we're talking about small amounts needed in the diet- less than 1% by weight.

Fish meal is the base and protein source for most prepared foods, but it's naturally high in phosphate, which is a big part of the reason that it's being partially replaced in feed for open pen culture (and why prepared foods aren't the best choice for display tanks). It doesn't usually have the phosphate preservatives added. These are mostly used on fresh and frozen seafood to help it retain moisture. Fish meal is a dry powder, so you don't want it to retain moisture.

all that being said I dont know why gelatin and preservative free frozen food would have excessive phosphates (say a package labelled 100% krill or mussells ect). dont they just catch it, cube it and free it? from my understanding all food or organic sources are going to have some phosphates but flake food is the main offender in regards to excessive phosphates.

The freezing process itself ruptures the cells and releases the juice inside, which is high in nutrients. Those that are water soluble will be lost to the tank water rather than eaten by the fish once the food is added to the tank, so it makes sense to rinse them off outside of the tank especially since you need to thaw the food before feeding it anyway.

[rickh]

Well I got out the PO4 kit and measured my Emerald Entrée. Yikes, a single cube melted in about a cup of water is off the charts.

So I did 6 serial dilutions and the PO4 is still detectable by my lousy kit. I believe if there are any particulates in the test sample you will get a positive test.
I emailed the manufacture about this several months ago and they said not to wash their food. All the "goodies" will be lost.

I haven't been washing and the fish, coral and nuisance algae are doing great. Even with a refugium and a PO4 reactor.

The fish and coral are the easy part of this hobby. The battle against algae drives many people away.

[rickh]

Tonight I put my standard amount of dry flake Formula Two in a cup of RO water. Let is vegitate for a few and then measured the PO4. Not as high as the frozen cubes but still >5 by my kit.

What's a guy to do?? Anything that has protein is going to have phosphates.

[MileHighFish]

Thanks for doing that rickh, I figured the dry food might have more PO4.. LOL guess Im wrong..

[drparker]

I feed Rod's Food, a frozen mix and don't rinse it. My tanks seem to love it. Here's what his web site says.

Ingredients: Shrimp, Scallop, Oyster, Clam, Squid, Octopus, Brine, Krill, Mysis, Grouper (or perch), Red Nori, green Nori, Broccoli, carrot, Frozen red plankton, Golden pearl (7 sizes), DTs Oyster eggs, Selco, Fresh hatched brine, Freshly harvested rotifers

Should Rods Food be rinsed before using? NO! Rinsing would wash the small particles in Rod's Food away. All ingredients are rinsed thoroughly before Rod's Food is made.

[rgrobe]

drparker

There have been several frozen foods that claim to be low in phosphate. I tested mine and was surpised that the waste water tested so high.

Could we convince you to sacrifice a cube and a PO4 test? It would be good for all of us to know if the claims that Rod's makes is true.

[drparker]

Sure but the only test kit I have for PO4 is a Elos, will that work? Rod's is a sold as a thin slab and not in cubes, so how much? Should I add some tank water there's not a lot of water to it, not like squid.

[rgrobe]

The Elos test will work fine as long as it has not reached it's expiration date.

I feed two cubes which is what I tested. I don't think it is necessary to test that much if you feed less. On a flat sheet try a 3/4" square. I let mine soak in about 1/2 a cup of tank water until the food was fully thawed, Then I drained the water and food through a fine brine shrimp net. I drained the water into a container under the net. You can keep the food and feed your tank as usual.

Just take enough of a sample from the waste water and test for po4. It will be good news if your results are low but you may also find that it is higher than you'd like.

Thanks. let us know how it turns out.

[Frick-n-Frags]

bingo!: anything that has protein, has phosphates = building blocks of protein

IF 100% of this food with its PO4 load is eaten by the tank inhabitants, you have hit the ideal goal.

the rinsing, eliminates a KNOWN portion that isn't going to be eaten, thereby putting you closer to that ideal. yes some micro food is lost, but if only 10% of that gets snagged by filterfeeders, still a better bet to rinse....

[CIGDAZE]

Originally posted by rgrobe
Ok, so this evening I pulled out a cube of mysis shrimp, cube of brine shrimp, and 1/2 cube of cyclopese. As usual I filled a small container with 3/4 cup tank water and allowed the food to thaw completely. I then poured the food and liquid through a very fine brine shrimp net and collected the water in a second container. I allowed the water to settle to make sure there were minimal particulates floating.

I first tested my tank water using the Hanna and got a reading of 0.02 po4 which is consistent with my previous readings. I then tested the water that was used to thaw the food.

Wow, I don't know how scientifically accurate the procedure was, but I was shocked to find that the water tested at 1.95 po4!

With readings that high I am sure that over a period of time the cumulative effect would certainly add a significant amount of phosphate to the tank.

While I have been rinsing my food for some time, I am now convinced it is worth doing.

I concur with your results. I did the same thing with an API phosphate test. I added one cube to about a 1/2 cup tank water and the color of the tested sample turned black like coffee. There's some major amounts of phosphate in those little cubes.

I learned the hard way. I used to just thaw the food in a small amount of tank water and then feed...well, it didn't take long for the effects of phosphate to start showing up in the form of GHA. What a PITA. Now, I thoroughly rinse the foods with fresh water and run a phosban reactor for good measure. Things are much better now.

[snorvich]

I rinse all frozen food (except cyclopeeze) and run a phosphate reactor. Sure, it reduces the convenience factor by a minute, but fighting algae is a royal pain.

[paraletho]

I guess I'm one of the lucky ones in the hobby living right close to the Gulf of Mexico I feed mostly fresh. Once a week I get the cast net and collect small shrimp and silversides/menhaden. I guess I should say lucky for the fish since Ike washed the whole d#%* house away. The tank was next door at my sons house 18 ft. above sea level on steel I-beams. Its still cadillac'n.

[drparker]

Originally posted by rgrobe
The Elos test will work fine as long as it has not reached it's expiration date.

I feed two cubes which is what I tested. I don't think it is necessary to test that much if you feed less. On a flat sheet try a 3/4" square. I let mine soak in about 1/2 a cup of tank water until the food was fully thawed, Then I drained the water and food through a fine brine shrimp net. I drained the water into a container under the net. You can keep the food and feed your tank as usual.

Just take enough of a sample from the waste water and test for po4. It will be good news if your results are low but you may also find that it is higher than you'd like.

Thanks. let us know how it turns out.

Ok, I soaked the square in tank water poured it through a net but I don't have a really fine brine net. I let that set for an hour but it never really settled, it still had a lot of suspended particles because of the red plankton, Golden pearl, Selco and rotifers in the water.

I tested straight tank water and this water.

Tank water = 0 for PO4

Water from Rod's food about halfway between zero and .01 for PO4

Here's how I got there. After adding the test solutions to the water and waiting two minutes the suspended particles started to change color and settled on the bottom in two layers. A thin dark blue layer that was off the chart above 1.0 and a 1/4 layer that was still suspended but dense enough to settle, it's color matched about .75 on the color chart. I then poured the top layer of solution about 7ml that had no particulates into another vial and it measured halfway between 0 and .01.

So my conclusions is that he rinses pretty well but still has a slight .01 for the PO4 and that the food itself holds a lot of PO4.

This matches with my experience of feeding Rod's twice a day in two different tanks over the last 18 months and I have no algae problems. I do run skimmers and have a GFO reactor as well as a fuge with slow growing cheato.

[rgrobe]

Thanks drparker. It does sound as if Rod's is rinsed better than the avarage.

[redfishsc]

I gotta pick up some of Rod's stuff. I have never once heard a complaint about it and everyone loves it.


I'm one that does rinse any "larger particle" frozen food, like mysis. Cyclop-eeze, I don't rinse, although I suppose I could use a brine shrimp net, but it would be a pain to get them lil buggers out of the net.

[MileHighFish]

Originally posted by redfishsc
I gotta pick up some of Rod's stuff. I have never once heard a complaint about it and everyone loves it.

Ditto, my LFS doesnt carry Rod's