Lets talk plastic barrels for mixing stations

[mvallee]

I have a mixing station I bought used made of 55 gallon Brute barrels. Markings on the bottom classify the plastic as LDPE (Low Density Polyethylene). For reference here is a link to the barrel in question Rubbermaid White 55 Gallon container

For the past 2 months I have been struggling with Cyano and Dino's and I have been trying to let them run their course performing 20-25 gallon water changes every week but instead of getting better it was getting worse, I bought a handheld TDS meter and found the RODI water in the bucket I was using for top off and salt mix was reading between 5 and 6. I emptied and washed the barrels and made a new batch of water and the reading straight out of my RODI and in the bucket was 0 so the TDS was coming from sitting in the barrels over time.

Should I be looking to change out my barrels for something else? I can not find anywhere that says LDPE is considered ok for potable storage of water although it used in food and juice packaging.

Thoughts, should I be looking for something different for my mixing station? Does your plastic storage and mixing barrels add TDS to your RODI water and this is just normal? I typically top off my barrel every week so water is always sitting in it.
Also if anyone knows of a local place that sells plastic barrels that are better for mixing station/water storage please let me know

 

[kgstei]

If you were using the barrels for salt mixing, then you would get a tds reading from residual salt.

 

[mvallee]

If you were using the barrels for salt mixing, then you would get a tds reading from residual salt.

I have two barrels one for the RODI water that I then pump into the second to mix the salt in so salt never goes in the first.

 

[kgstei]

Got it. Do they have covers? Now that you have a tds meter it will be interesting to see what the stored water tests in a couple of weeks.

 

[mvallee]

Got it. Do they have covers? Now that you have a tds meter it will be interesting to see what the stored water tests in a couple of weeks.

they do have the covers and they fit very well, I am filling it halfway now and we will see what it looks like by next weekend.

 

[cilyjr]

I did some looking into plastics a while back here's what I found (I wrote this for a thead a whike back)...
there are 3 types of food safe plastics commonly available on the market.
1. HDPE (high density polyethylene, recycle code 2) is the most common because of its rigidity. Pretty much all 5 gallon buckets are made of it. it is also what the large brute containers are made from. I use these in the restaurant to store flour sugar ect. and can be bought at any commercial food service suppliers, from home depot, and lowes with caution. it is important to note that NOT ALL HDPE is food safe however. this is because as it is molded, a release agent is sometimes used in the manufacturing to make it easier to remove from the mold. many release agents are toxic.

2. LLDPE or LDPE (linear low density polyethylene, recycle code 4) is less rigid. Most of your rubbermade containers are made from it. We use these in the restaurant to mix and hold things like coleslaw and large batches of orzo salad ect. these can be bought from commercial food service suppliers, home depot, and lowes and have little risk of not being food safe they are however less rigid (think of a bucket you use to put fall leaves into) and may not be the best for long term storage because of the possibility of becoming deformed. I find containers that use this plastic personally as its cheap and easy to find and because of its flexability it doesn't have the same mold release issues HDPE has. but I do worry about them breaking.

3. PP (polypropylene, recycle code 5) it might be hard to find a large container made of PP. it is mostly used in those little brown bottles that your prescription pills came in and the disposable ziploc containers with the blue lids that have taken over your kitchen. the issue with PP is The Environmental Working Group classifies polypropylene as a low to moderate health hazard. they state "two substances found to leach from polypropylene labware - an antimicrobial chemical known as quaternary ammonium and a plastic softening agent called oleamide" this might be only because PP is used in some makeup as an ingredient.

the other plastics i would not use though they are in many bottles one finds food in is PETE (polyethylene terephthalate recycle code 1) as it is known to leach BPA over long periods. and OTHER (other recycle code 7) this really speaks for it self. it is anything that does not fit in the other categories. it could be ok but you cannot know.

finally vinyl (PVC recycle code 3) strangely not considered food safe due to the use of phthalates to soften the plastic. many companies are using non-phthalate plasticizers since 2010 so it may be changed at some point.

thats what I found. my curiosity was piqued for both the hobby and my work (a few years ago when the #7 plastic ban happened due to bpa) anyway thats what i found i hope it helps

 

[nemodan]

I have been using these for the last 4 years. When I got them I checked them for TDS leaking during several weeks. And NO TDS.

http://www.rubbermaidcommercial.com/rcp/products/detail.jsp?rcpNum=2632


From the description:

Meets NSF 2, 21 approval and is USDA Meat and Poultry Group listed, ensuring regulatory compliance for food storage and clean ability.

 

[Andy V]

The Environmental Working Group is not a respected organization. I don't know if they are wrong on this particular issue, but they are not taken seriously by most scientists.

https://www.acsh.org/news/2017/05/25/dear-ewg-why-real-scientists-think-poorly-you-11323

They are some of the worst people that the media somehow gives credibility to.

 

[jasonrusso]

RODI will absorb TDS out of the air. I don't worry about it. It's the stuff in the water that you don't know is what I want to filter out