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

Input:
Question: Do you have to stack all trays if only filling one
Document: I bought this model as a replacement for one of a different brand that I gave my son when I relocated. It works wonderful, the only drawback is the design of the base unit. Dripping got into the outer edge the last time I used it and that area is difficult to clean. I bought 3 additional sets of trays and am able to make ten pounds of jerky at one time.
I love that the trays stack,  you have temperature options and I even bought a set of extra trays to add on top. It is a bit annoying, but I fill it and set it up in a spare room and shut the door.
It's not the nicest dehydrator out there, and I'm sure the more expensive ones would dehydrate food faster. But it is a good dehydrator, and dries fruit out evenly. The higher you stack the trays, the slower they dry so keep that in mind and always check something from each tray (like the instructions say to), not just the top tray. Overall, I am happy with my purchase and will be using this for years.
I got two extra trays when I bought mine. Right now I have two trays of pineapple, three strawberry, and three with apple drying. It is so easy to work with and stack together. I'll post an update when everything is done. I also ordered two extra screens, and liked them so much ,I  just ordered two more. Now I have 8 trays and 8 screens. I'll be doing turkey and chicken jerky next week. I'll give another update on that also. Thanks Presto, and Amazon.
It dried y fruit and I'm pleased with the temperature setting. I wish they sold this one in target and other stores, but I could only find this presto online.
This is a great dehydrator, works well, i reall like the temp adjustment. It is made so that the drying racks stack into each other which is a nice space saving feature.
An excellent value for the money. The only detractions are, it's noisy (fan) and it lacks a self timer. The sections stack neatly in the unit and are more than adequate for drying fruits and jerky.I recommend this product so long as you can live with the noisy fan.
amazing product, works well, good for beef jerky,  I like the temp control,and the stackable trays save you room and easy  to clean.
We have used this dehydrator many times and it works wonderfully. The fan is a little loud. I love that the tray all nest together, and it doesn't take up very much room. The trays clean up easily ( we use our dishwasher on a cool setting). We have made so much jerky that this product has paid for itself in only a short time.
You NEED the temp change. It seems like they could have had an off position for the device (instead of having to unplug it) but not a big deal. Cord is also VERY short!
Answer: No you can sack only one, or as many as you want.