Upcycling 30 gallon barrels from carwash - what is your opinion?

These barrels were cheap!
5 dollars for 30 gallon barrels.

Then I realized they had soap chemicals from a carwash.  

I bought 6 of them.  Is there any way to clean them out enough so that I can use these as water reservoir for drip irrigation?

Online was saying they wouldn't hold water in these because of forever chemicals, but I did not know if this would apply to drip irrigation.  

Could I put a filtration layer of stone, straw and charcoal in the bottom?

The barrels are white, which is another oversight on my part (due to algae).

It would be nice to cut these and do some aquaponic tanks or something...... But still am worried about chemicals.

30 gallons worked well, because I could fit 4 of them into my Ford focus, and I might not be able to fit a single 75 gallon.  

Would you happen to still have the labels or access to them that came from the barrels?

I would recommend looking at the SDS of those barrels to know what was inside of them. I would then make the call on what I would use them for. Sometimes the barrels can be cleaned out and you can have confidence that there won't be residue but if the hazard ratings are high, sometimes its better to be safe in my opinion.

If you cannot locate the SDS,  see if you can find a supplier of cleaning materials for car washes.  They may be able to identify the origin of the barrel and original contents.

No label, but I can ask the guy for the msds.  That is a great suggestion

If you do manage to get them clean and safe to use, to solve the "white" problem, consider building a box out of scrap material to enclose them and keep them dark.  My sister can't empty her rainwater barrels because then the wind tips them over. A box would solve that issue also.

Agree, check the SDS.

After I wash pails that held pool chemicals (chlorine bleach, strong alkaline) I fill them with well/rain water and let them sit until the algae is growing on the inside walls. At that point I think they're pretty safe for plant water use.

Sds and label unavailable.  
They said could have been a number of things

Now I can brainstorm what to do with 4 nice barrels.  

Perhaps a gold sluice system?

Maybe a garden pond/birdbath possibly lined with a tarp.

They were going to be the base of hydroponic towers, but I have lost confidence in them.  5 gallon bucks are 3 bucks with lid here food grade, so there's no reason to take chances.

Any ideas?

I might need to give them away

William Wallace wrote:They said could have been a number of things

Such as?
1. Were they used by the car wash? Or did they get them from someone else and decide they didn't want them?
2. If car wash, what products did the car wash use?  Detergents? Or things like car wax? Or more dangerous things like upholstery protectors? If you can narrow that down, you may be able to find "antidotes".

The big antidotes for many chemicals are microbes. If you're willing to take the top off one of the barrels, consider making compost tea in it. Then consider filling it with substrate and growing mushrooms in it (but don't eat them). Then maybe try Douglas' idea of growing algae in them.

The issue is the "forever" chemicals and figuring out just how "forever" are the ones that may be in the barrels. There are microbes that eat plastic. But the 3M anti-stain chemical is pretty forever and I'm not aware of anything that eats it at this time.

Barrels have a ton of uses, even if not suitable for food/garden work.

I have a few in my outbuildings that corral shovels, rakes, hoes, brooms, all that long-handled stuff. Loppers and hammers hang on the outside edge. It makes a lot of gear immediately accessible with a tiny footprint in the building layout.

Dad and I cut 220L barrels in half for big buckets for earth moving, gravel… 30 gallon versions could be a more back friendly version of that.

Appreciate the suggestions for the 30 gallon buckets, and I intend to put some use to them. I just really only had room for irrigation barrels in my garden, and no extra storage space.

Instead, I just bought 100 5 gallon buckets, and fit them all inside my 4 door Ford focus.  These were food grade, with lids, at 1 dollar a piece.  The downside was an hour drive each way ( hence the full 100).  

I could still see out both side mirrors and my rear view also. How?  They are rectangular buckets. I really like that, because it is much more efficient space-wise in the garden.  Sitting beside another, there is little lost space.

It looks like I am going to do quite a bit of kratky planting, with zero prior experience. My thought is that these will stack much better than the round buckets.  I have been searching for cheap ways to make an overhead pole for suspending plants from, and these buckets filled with water (and plants) might be the perfect.  I was thinking that I would do two columns stacked 5, 6 or 7 buckets high with a pole lashed to the top of both stacks..

Expanding the single bar into a plus sign with three more columns and three more bars would be the most efficient. A plus sign 6 buckets high would then be 30 buckets.  Now to figure out the poles.....

The barrels I inherited were from dairy equipment disinfection.  I use them for wicking planters. They fit on a hand art better than 55 gallon barrels for moving into the greenhouse for the winter.