Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: Will the units fit together when stacked so as they remain stable?  If so, how many units high can they be safely stacked?
Document: The bottoms have notches in them so they can be stacked cross cross and the handle and caps of the lower container fit nicely into the bottom of the next.About the only thing I thought would be a good addition is to have water treatment instructions on or with the drum for the average consumer. However, this info can be found on many websites but usually is for 55 gallon drums or 1 gallon ratios.
We bought 8 of these, since we have limited space and they say they can be stacked.Filled them up and stacked them, then got curious to see how high they can stack, since they are quite heavy full.Amazon description didn't tell me (should have read the reviews, dangit! ), so i check the manufacturer website. Buried in the FAQ's, it says they can only be stacked empty, not full.What is the point if you cannot stack them full?
I purchased this along with several other water jugs to carry water in on a fly-in fishing trip recently. It's a high quality jug and the spigot is heavier duty than my old jug and that one lasted 10 years so I'm thinking I'll have this one for many years to come.
I purchased this product for emergency water storage and wanted to be able to store them in a small space. Based on the description, I stacked them 2 high (the bottom is cut out so they nest well). Due to the weight and weak plastic walls, the bottom one developed a crease in the plastic at the corner and consequently a hole. I called the company  to discuss the 5 year warranty and they indicated that the products are only stack-able when empty. This is questionable advertising at best.
I have found too many times that when you store water in plastic containers the water develops a plastic taste that I find down right icky! The term Icky is a posh scientific word don't you know. All plastic containers will impart a slight plastic taste to the water stored therein but; some are worse offenders than others. In this case the Reliance Products Aqua-Tainer 7 Gallon Rigid Water Container is one of the better water storage units.
I bought two of these containers to have on hand, just in case. The units are well made and seem substantial enough to serve under continuous use.
this item should have multiple sizes avail to fit hoses onto the cap. Unlike the flojet water pump which comes with other hook up sizes. Had to do more searching around at other stores other than that its ok
This keeps a small stack stable, and less likely to fall.Price is right (cheaper than at the sporting goods store), and with free shipping it was an easy decision.
Well built. We have containers around out home for a variety of liquids, but did not have anything that could hold potable water. This seems to be a perfect fit as a means to store drinkable water for camping trips or to use as water storage in case of an emergency.
There was a very slight plastic aftertaste but you had to work to sense it. The units are made to stack easily to maximize space and store easily. The price is right. The storage capacity makes them a bargain at the price. I use these water storage units because; occassionally my condo building turns off all water to allow unit owners to make repairs.
Answer: yes