Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: How do you get rid of the brown build up that forms on the bottom of the tank? I can't fit my hand in, and a diluted bleach solution doesn't do it.
Document: This humidifier is so quiet you can't even hear it running. You can adjust the output from a fine mist to a fog. Doesn't leave everything around it wet or even damp. Be prepared when you fill a 2 gallon tank it will be heavy, have a good grip on the tank,  I will be ordering a second one for the bedroom,
We use this humidifier in the bedroom. It's not completely quiet, but it is okay. I like the way it doesn't need to be refilled very often. I love the way it produces so much mist. I am still perfecting my technique in refilling it:  removing the round cover on the bottom of the tank, securing the cover again, carrying the heavy tank, and placing it just right on the white base.
I bought it in late April 2013 and used it only for 2 months. I did not use it over the summer. I started to use it again in beginning of October 2013 and found that the unit leaked from the bottom and made the whole floor wet. The unit does not work any more.It is a bad design and not worth buying at all. Better buy other name brand.
I use the humidifier in the bedroom at night. With the output knob at about half way, it gives adequate moisture in a medium sized room. I gave it a 4 star rating because the top isn't flat. (Surely the manufacturer can improve on this?) It can't be filled to the top in this tipped  angle. I would recommend this product, but be aware of the filling problem.
The thing is either on or off. Fortunately, &#34;on&#34; produces plenty of mist but not so much that the floor directly beneath it isn't soaking wet. So, bad luck to get a control that doesn't do anything much; good luck that its one setting produces the amount of mist I want. I realize this is why I gave it four stars, so my rating is very subjective.
I reviewed all of the other comments (many not good) for this unit and still decided to purchase it. My first one that I received is working fine. I just received my second unit today and have not filled and started it yet. So the jury is out on that one if it is a viable unit or not. I decided to elevate my first unit up about 1'+ above the floor and with doing this the mist does not seem to get the floor wet below it.
I could not get it restarted again. Needless to say I wasn't too happy. I called Amazons Customer Service and explained my dilemma to them. In less than 24 hours FedEx was at my door with a new replacement unit and all the paperwork for free return shipment of the defective one. I was very impressed with the way Amazon handled this unfortunate situation.Lets hope I had the only bad apple in the warehouse, and I would still recommend this humidifier to anyone.
My sunTown su-2000 went bad so I looked for the replacement and this one seems to be its new version. I going to pay more attention to see how long it lasts and if it last 2 years ill be happy. The old one slowly took more and more time to be on from 5 mins to 20+ mins to try and get the same result. Huge amounts of cool mist comes out that you can see. I used distilled water in mine to prevent mineral issues/residue.
It works very well, it holds enough water to run non stop at full for 24 hours.You need to wipe it down inside base and bottom of the blue holder to keep clean.Good product and easy to use!
The humidifier works well so far (we've been using it for 2 months). It doesn't require filters, so it saves you that maintenance cost. My only complaint is that the outlet for the mist can't be adjusted upward, so it tends to leave a damp spot on the ground in front of the spout.
Answer: Hello. I take a dish rag, pour alcohol on it, place it inside the unit. I then use a long wooden kitchen spoon to move the rag around to clean the build up. For the harder to reach areas, I have a long thin brush that was originally purchased in a 3 brush set to clean my fish tank. Those work great. I also use q-tips dipped in alcohol to clean the inside of the detachable parts. Hope this helps