Conducting a Food test for PO4

[seaham358]

Ok I read all the time how food can cause the PO4 to raise... So I'm doing a little test.
RO/DI water with 0-PO4 and a pinch of 2 kinds of flake each in there own glass and some Mysis and Brine mixed. One is RO/DI and the other has some tap water. The date is wrong on the notes, test started today.... Will post results later.

 

[Jermz79]

Cool ... once you figure out the numbers and what not if you could also post what "Brands" you used that would be great!

 

[hackteck]

interesting test i was thinking of the same exact idea but was just to lazy to do it hehe let us all know the results

 

[seaham358]

San Francisco Bay Mysis and Brine shrimp
Ocean Nutrition Prime Reef
Brine Shrimp direct Plankton Gold Flake

 

[melosu58]

Cant wait for the results. That`s a good idea.

 

[seaham358]

Tested and they hit 3+ on the PO4 meter, 3 is as high as the test kit goes.. did not test shrimp and tap water after the positive on the shrimp and ro/di.
It was really dark blue... The Prime was a 3 but slightly lighter then the others.

I drained off most of the water on the shrimp and filled with ro/di and retest to see if draining off the juice from the thawed shrimp makes any difference.

 

[seaham358]

Tested Shrimp that was drained of 90% of its fluid and then had ro/di added to it and it tested at 3 and I also tested a piece of Nori that was in ro/di and it tested at 3 PO4.
So you can't add any food with out some PO4 getting in the tank..

 

[Fluff]

Nice experiment seaham. Thanks for posting this. PO4 then is just something we have to deal with and try to regulate so it doesn't get out of hand. It's interesting though that even in draining and replacing the ro/di water, the shrimp still tested so high.

 

[seaham358]

I thought for sure that after draining most of the fluid off the thawed shrimp it would be lower.

 

[Fluff]

Yeah, I've been draining and rinsing my mysid for months thinking I was helping. Perhaps it did a little, but it would seem only a very little. :?
That's why I find your test so interesting.

 

[melosu58]

Nice experiment Seaham. Been always wondering about that.

 

[tecwzrd]

I really appreciate you taking the time to do these tests seaham358.

I’ve also tested my flake (Prime Reef) and frozen (Marine Cuisine) but tested 1/4 teaspoon of flake and ¼ of a cube in one gal of water and after a couple of hours I had much lower results of 1 ppm for flake and .5 for frozen that was drained. Even that sample amount was 10+ times the amount of food I ever add per gal. ie: I feed on average 1 to 2 cubes of frozen every other day for my 55 gal tank.

I think it’s the amount of food versus water that is causing such high results.

Using small cups and adding food that covers the entire bottom is the equivalent of dumping 5+ lbs of food in a 55 gal tank and trying to measure the po4 readings you get and wondering why it’s off the chart (drained or not drained with frozen)

I think if you use a larger water sample and/or less food you would have more accurate readings and be able to distinguish between flake/frozen/drained frozen much easier. I haven’t tested the frozen drained and un-drained yet but it probably is negligible. I mostly drain for peace of mind like never adding lfs tank water to mine since I really don’t know what it might contain.

Most of us feed pretty sparingly every other day and most of the food we do feed is consumed within minutes and anything that falls to the bottom would be consumed by hermits/snails within 20 minutes.

I agree that any food we add to the tanks can/will increase po4 very slightly but with a good clean up crew/PWC schedule/skimming should still keep it undetectable.

 

[cmor1701d]

I think it’s the amount of food versus water that is causing such high results.

Good point

I haven’t tested the frozen drained and un-drained yet but it probably is negligible.

What are you waiting for We're all anxious for the results of that test too.

While you're at it how about testing a sample of blender mush too?

Thanks to both of you for testing and sharing.

 

[hackteck]

heres what im wondering can a tablespoon or so of po4 water contribute to an algae outbreak? sounds kind of hard to believe

 

[tecwzrd]

IME for tanks that have po4 accumulation is usually either the result of overfeeding flake or frozen or po4 in the PWC water. If you overfeed or use water that contains po4 you will usually have algae problems.

As long as you use po4 free tap or ro/di and feed sparingly you should never have po4 readings in your main.

Unfortunately most po4 in the tank will not be readable with test kits if you do have an algae problem due to the algae using up the available po4.

If you do get a reading then it’s probably much worse then the actual reading itself.

 

[melosu58]

Thasnks for the time and effort seaham.

 

[seaham358]

I only used a pinch of flake food and a good chunk of mysis and brine. I think most people thaw there frozen food in a small cup with maybe a little water, not a gallon like you tested.
I know adding more water and using a larger cup would give a different results. The purpose of my test was to see if there was really PO4 in the food I used by. So now I know for a fact that all my food can create a PO4 issue if I over feed.. Which I do

And its a no brainer that dilution is the solution to pollution..

Over time if food builds up it will produce PO4 thats a fact..

And imo most people like to see the fish active and feed every day, I know I do..

I was not trying to conduct a scientific experiment here... I had to work the late shift, I was too lazy to do yard work so I said hey how can I kill a few hours... Video games of screw with the tank..
All the true scientific stuff I leave to Steve S.. That is his field of expertise..

 

[Brenden]

I always drain my frozen food after it is thawed. Steve who?

 

[rayjay]

Most of us feed pretty sparingly every other day and most of the food we do feed is consumed within minutes and anything that falls to the bottom would be consumed by hermits/snails within 20 minutes.

Feeding sparingly and every other day must be a local thing, as around here, most that I know feed twice a day.
Although every one I know uses snails and many have hermits, I don't have either in any of my tanks, and my tanks are bare bottom.

Now, someone with time on their hands, and a little expertise and equipment, could experiment to find trace elements that get dosed with the foods we feed the tanks.
Most trace elements won't just leach out like the phosphates though, as the food would need to decay to release much of the contained elements involved, similar to the detritus release of elements in our tanks.
Because I feed often and in considerable amounts, I do water changes not to replace trace elements, but to reduce the buildup of trace elements do to feeding my tanks.

 

[cmor1701d]

Feeding sparingly and every other day must be a local thing

No, There are members on this board from around the world. It's just good advice to help keep maintenance (PWC) to a minimum.

It's not trace elements you're removing with PWC's but excess nutrients.