Egg Crate Phosphate Contributions

[stcreef]

This post was split off from the original thread where the question was raised: "is eggcrate ok to use in frag systems". This part of the thread took on a life of its own and deserves its own thread. --Phyl



The lighting diffusers "eggcrate" everyone usually uses from the big home stores is made of polystyrene. There are no phosphates in the polymer. It is a thermoplastic, so unless you plan on melting or burning it (those nasty phenyls get released), it is safe to use.

With that being said, it is not uncommon for the manufactures to spray anti static liquids or cleaning agents on the final product after manufacturing. So be sure to thoroughly clean before use.

 

[Phyl]

Re: Propagation Tank Setup Help.

We always get an algae bloom from fresh egg crate. If you want to avoid that you could "cure it" in a dark tank before using it in the prop. I'm shocked to hear that they don't leach PO4 based on this experience, but STC seems to have a great knowledge base on this stuff. Interesting.

It woud be fun to test a piece of eggcrate in Saltwater to see if it does in fact leach PO4 from some place (antistatic/cleaning agents/??) when placed in SW for the first time.

 

[stcreef]

Re: Propagation Tank Setup Help.

If it is white "eggcrate", the styrene is pretty pure. Any other color and there is a high chance that there is recycled components to it.

Also remember that that there may not be PO4 in the "eggcrate" but the styrene is a hydorcarbon product. Un bound hydrocarbons in the plastic will leech. Which can cause PO4 that is already bound in your tank to precip. But the amount of leeched hydrocarbons would be undetectable at most with the amount of eggcrate most use. If you see this regularly using eggcrate, I would be more suspect of the antistat or cleanser. Give it a good acid wash (vinegar dip) before using.

I may stop at each store tomorrow and pick up some of this eggcrate and give it to the lab to test. Put this whole thing to bed.

 

[Phyl]

Re: Propagation Tank Setup Help.

Very cool. So if fresh egg crate could cause the PO4 to precip out (which actually results in algae growth ON the eggcrate), could keeping a good supply of fresh egg crate (or some commercially available unbound hydrocarbons) reduce PO4 in the tank?

Inquiring minds want to know! LOL!

And I'd love to hear the results of the lab test!

 

[stcreef]

Re: Propagation Tank Setup Help.

Ok without giving away trade secrets, I have just been informed that the principal ingredient in antistat for styrene is ammonium alkyl phosphate (sort of) ((which can create some crazy salts in the right conditions)). It is water soluble and a vinegar solution should be the simplest way for a home user to break it down.

The cleanser may be another issue all together. So i'll have some tested.

I was also told that there maybe some antibacterial agents sprayed as well.

So the above being the case, Phyl isnt off by saying "cure it" before use. But its not the plastic causing the bloom. Its all the other fun stuff sprayed on it. So no leeching, just straight dissolving.

 

[Phyl]

Re: Propagation Tank Setup Help.

Brilliant. Thanks! Where were you two weeks ago before I put that egg crate pile into my tank!?

 

[stcreef]

Re: Propagation Tank Setup Help.

Another note that was just brought to my attention. Because these eggcrates are UL listed. They will have a flame retardant in them. Usually Triphenyl Phosphate. It is also water soluble. However its solubility is degraded in natural seawater. (35% in 14 days) But in non-sterilized freshwater it should fully degrade in a few days.

I just had a chem eng's head explode when he tried to figure some of the chemical reactions that could occur in an enclosed reef system.(not related to this topic) He actually got frantic. I think he wore out my whiteboard.

So again "cure it" first would be the way to go.

Phyl, this is probably the cause of your algae outbreak. Good old flame retardant. Look at the plus side, at least your tank wont catch fire.

 

[stcreef]

Re: Propagation Tank Setup Help.

OK here is the skinny in the eggcrate. Stopped and picked up some samples lastnite and gave them to the lab this morning. The guys were excited about this, something different to do I guess. They ran the whole gamut. Mass spectroscopy, chromatography, ionic and hydrocarbon contamination etc.

So on to the results.....

The big standouts were tricalcium phosphate and some traces of mono and diphosphates. These are typical of the antistat and anti-lumping agents. Total volume was <0.10% by volume.

So they started testing to see if they could dissolve the phosphates out without destroying the eggcrate. They found that the phosphates are bound pretty well and could NOT be drawn into solution just with water or sea water. But they did find that they could draw it out pretty easily with a calcium hydroxide solution, which we all know what that is, I hope.

They are now testing an acid wash to see what effect it has.

Stay tuned..........

 

[stcreef]

Re: Propagation Tank Setup Help.

Oops that should read <0.10%, could a mod change that?

 

[stcreef]

Re: Propagation Tank Setup Help.

Thanks Phyl for changing that.

It appears that vinegar is bringing the phosphates into solution as well as some phenyl, however because these are impregnated within the styrene prior to molding it is taking longer that expected to get desired results. The saving grace to this is styrene will absorb the solution (about 3%). So we just need to determine the time needed. The solution is typical white vinegar keeping the louver submerged. Sampling the solution every hour for content. Based on current results it would take a few weeks to remove the phosphates with just vinegar.

I am starting to believe it may just be easier to track down acrylic louver rather than use the styrene.

 

[GregW]

Re: Propagation Tank Setup Help.

So you saying that the common eggcrates aren't leaching phosphates into our tanks?

 

[Phyl]

Re: Propagation Tank Setup Help.

I believe he is now saying that they ARE leaching PO4 into the tank at a slow but measured rate and it would take weeks soaking in vinegar to get rid of it all. There is (according to what I've read above) some acrylic version that doesn't have the PO4 issue?

 

[jceli728]

Re: Propagation Tank Setup Help.

Has anyone tested Home Depot or Lowe's eggcrate for phosphate? or notice a Phosphate increase after adding to tank?

 

[stcreef]

Re: Propagation Tank Setup Help.

The answer to all the above questions is: Yes, the eggcrate from Lowes and Home Depot ARE definitely leeching PO4 as well as some phenyl. I bought samples from both stores and gave them to the lab. I will have to go back and get the manufactures names to post here, because different manufactures use different compounds in their products.

I dont think its leeching as much as it is becoming available to organics in the water column right on the surface of the plastic. The phosphate compounds in the styrene wont dissolve easily in just the water column, but will react to other compounds in the column. So that is why you saw algae right on the plastic.

There is a louver manufacture in Pennsauken NJ called ALP. I know they make acrylic louvers (aka eggcrate). I may see if i can get some samples from them next week to test. I may know someone that works at that plant.

 

[stcreef]

Re: Propagation Tank Setup Help.

OK, an update on this so far.

After a week of quite a few samples soaking in different solutions and a few samples for control in tank water, it appears that the styrene louver really isn't leeching much PO4. After the first 24hrs there was a very slight increase found in any of the solutions. But then it tapered back down to next to nil.

The chem engs. suspect that the only PO4 being released is only from the surface of the plastic that never made it into solution before mixing with the other compounds. However, there is still ample PO4 available in the styrene. Hence the algae forming ON the plastic.

So up to this point it is a user call on whether to use the styrene eggcrate or not. You will be adding a potential PO4 source to your water, but it seems the small amount will be consumed by attaching algae.

We are still trying different solutions to removing the PO4 from the styrene (re: curing). I also have samples of acrylic eggcrate from a few vendors that will be tested next week.

 

[Phyl]

Re: Propagation Tank Setup Help.

In "production" the egg crate has stopped growing algae. So over the course of 3 weeks to a month, there seems to be no additional PO4 coming off of the eggcrate. It seems like the algae growth has consumed it and it has started growing coraline instead. Thoughts?

 

[Altohombre]

a football sized section of my metallic egg crate has melted the color off because of water splash and my T5's. Could this pose any possible problems for me? There has seemed to be no ill effects so far after about a month of this except for algae in the tank which I just attain to the tank being only setup in the beginning of January.

 

[stcreef]

Phyl:

There will still be PO4 bound in the plastic. But I wouldnt worry if you noticed that the algae stopped growing. This would indicate that the PO4 is sufficiently bound to no longer leech or be available to the algae.

Altohombre:

The metallizing used in the eggcrate is typically vacuum metalized. A mixture of more styrene and/or ABS with metal powders. If it was a silver/chrome look before, then it contained aluminum, iron and some lead as well as some other pigments. If it was gold in color, then it also contained copper.

 

[Phyl]

Probably in small enough quantities, but not stuff I'd want in my tank! Eep.