Our first step to take care of the problem was to start using all of the different choices from the local store.
Over a period of time, nothing seemed to do the job and even though the drain seemed to partially work, the water was still not emptying quickly. Finally I found something that worked like a charm. It cost very little and is more environmentally friendly than the chemical cleaners offered in the stores.
While paging through a book on baking soda uses I found a recommendation for using baking soda to clean drains. I was skeptical but intrigued. I usually keep a bag of bicarbonate of soda in our basement. I use it for softening wash water when doing laundry. A little helps to keep your clothes colorfast and fresh.
This is such a fun way to open a clogged drain because it is nontoxic and I'm amazed at how well it works every time I try it. I used one part bicarbonate of soda (baking soda) and one part white vinegar. The clog was so bad in the bathtub that I used approximately four cups of bicarbonate of soda with four cups of white vinegar.
A friend of mine owns an older motel and has had problems keeping the drains working well. She used the above suggestion and all of her drains are now free of clogs and she was amazed at how economical this formula is.