4.4 Gallon Stainless Steel RO Reverse Osmosis Storage Tank

Bought to replace the plastic-lined tank that comes by-default with iSpring Reverse Osmosis systems (which are otherwise superb). Installation was easy and so far the quality seems good - no leaks, no noticeable taste, and good pressure after two days, and I'll update if there are any problems. If you're bothering to use a reverse osmosis system to filter your water, I highly recommend this reservoir and suggest that you think twice before using a cheap one lined with plastic that is almost surely leaching estrogenic (hormone-disrupting) compounds into your water after elaborate (and expensive) filtration. If any reverse osmosis tank/reservoir doesn't clearly say that it is made from stainless steel it is almost certainly made from aluminum (which is much cheaper) and then lined with plastic (to protect the aluminum which would otherwise degrade and be much worse than drinking plastic!) It is the default in most reverse osmosis kits.If you are not familiar with leaching from such plastics, it is usually from "fillers" that are mixed into plastics during manufacturing to make them more easily handled, molded into desired shapes, etc. Unfortunately such fillers often have hormone-disrupting activities associated with everything from obesity to cancer, and because they are known to leak out of plastic over time they could be ingested by humans or animals. We still don't know exactly how much of a risk they are at the exposures that most people get - usually no one plastic product leaches a whole lot (drinking one plastic bottle of water is almost certainly safe), but lots of exposures through plastic bottles, food containers, canned foods (again aluminum lined with plastic), baby toys, etc could add up, and could combine with other environmental pollutants (including pesticides) which can have similar effects. We also don't know which fillers (there are many kinds put in many different plastics ) are most risky; BPA (bisphenol A) is a famous one that has gotten lots of press because it can definitely be harmful and is in all kinds of things, but recent research (see below) shows that other fillers can be just as bad or worse, including those that are now used in place of BPA.Predictably, plastic companies say plastics and fillers are completely safe, some regulation-inclined countries in Europe have already banned certain fillers, and US regulatory agencies are more on the fence, saying they can be dangerous in high doses but may not be encountered in high doses by most people. I tend to take a pragmatic approach and reduce my exposure when I can - for example by buying this tank which is a good bit more expensive than the default ($99 vs $35ish), but which will last me many many years making it pretty cheap on a cost-per-use basis. I try not to eat or drink much out of plastics, but if sometimes I want some pre-made refried beans I don't worry too much about one can here and there. If I had a child I would worry much more about their exposure than mine given how much smaller they are, how critical their hormone levels are throughout development, and how likely they are, especially at young ages, to go putting their mouth on everything :)If you'd like to know more about this issue these are pretty interesting readings:Recent findings from The University of Texas at Austin, that BPA-free plastics almost always contain other fillers that can be even worse:Bittner, Yang, and Stoner (2014) Estrogenic chemicals often leach from BPA-free plastic products that are replacements for BPA-containing polycarbonate products, Environmental Health, 13:41http://www.ehjournal.net/content/13/1/41A very good article in Mother Jones that covers some of the major health impacts and the uncomfortable history of the plastic industry trying to stymie or block scientific research into these dangers (similar to tobacco industry)http://www.motherjones.com/environment/2014/03/tritan-certichem-eastman-bpa-free-plastic-safeA recent report from the US EPA covering its approach to investigating BPA, and its current understanding (namely that BPA can be toxic, but that it's difficult to know the real-world health risks since many studies use higher doses than most people encounter, or use lower doses but have experimental design flaws that make them not totally reliable)http://www.epa.gov/oppt/existingchemicals/pubs/actionplans/bpa_action_plan.pdf

UPDATE: After using this tank for about 3-4 weeks, there was a major issue. The water coming out of the tank tasted strongly like rubber. I flushed the tank more than 5 times from completely full to empty. I tested the water with my electronic TDS meter. It was going into the tank at 52 PPM and after 24 hours of sitting in the tank, it came out at 198 PPM. So it was definitely leeching rubber chemicals into the purified water. This was shocking because this is the final point of contact where I am about to drink the water, AFTER it's already been filtered. So the fact that it put chemicals into my purified alkaline mineral water was not okay with me. I don't know if this is just a defective unit or if they are all like this but I am now engineering a tank system with no rubber bladder as well as testing other tank manufacturers to see if their rubber leeches chemicals as well or not. Try at your own risk.This is a beautiful tank. It IS lined with PP (polypropylene) which is a food grade plastic used commonly. Most tanks come with a butyl liner which is a type of synthetic rubber. So apparently, water is not coming in contact with the stainless steel. That is how all "bladder" style tanks work: they are lined with 2 bladders, and air and water bladder.See this image to get an example:www.purewateroccasional.net/Images/rotank.gifAwesome looking tank, DOES have a PP liner. Still better than a regular tank because it looks cool.Also it is true what another reviewer said in his comment: Stainless steel can release chromium oxide into the water. This will only happen if you are putting highly purified water into direct contact with stainless steel. That means RO and esspecially RO/DI water. You don't want to put this water on direct metal of any kind because since it has be purified, it has been deionized (in the case of RO it is not 100% deionized but very close. In the case of RO/DI it is 100% deionized).The issue is that deionized water is highly polar and has a strong ionic pull. In other words, pure water always seeks to dissolve something with ions in it. Research shows that deionized water can pull of some chromium oxide from the stainless steel into the water. How much, I do not know. Therefore I would conclude it could also possible pull off ions from PP and leech it into the water.This shouldn't be an issue anyway because the water isn't coming in contact with the stainless steel, but the pouch inside the tank instead. It is a butyl / rubber bladder that is supposedly lined with Polypropylene.Ultimately you don't want to be drinking RO or RO/DI water anyway. Because the same that it does to metal (dissolve ions), the same that is does to your body (it pulls ions which are mminerals out of your body and causes significant mineral loss.Summary: You should re-mineralize or alkalize your water with calcium carbonate and/or magnesium oxide before drinking and before sending the water to a storage tank! This is simple by adding an inline cartridge or extra housing just after the ro or ro/di system, right before the tank.

Nice product. Delivered on time and as expected.