Hi Jennifer,

I have 7" all foam, non-toxic foam, mattresses that would be perfect. They are high density, USA made, no toxic chemical fire barrier, and they are $399 a piece, free shipping to your house. Also, I have the Sparrow mattress, organic cotton, organic wool and Oeko Tex certified latex for $599 a piece, free shipping, and they are 7" also. You can call our store to learn more if you'd like.

Hi,

I would recommend a mattress 5-6" thick so its not too high and thereby safer.

If using on a solid platform, try putting some polyester batting under the mattress to increase ventilation and prevent mold.

I'd recommend our 4" of our d34 grade with either a 2"memory or 2" egg crate on the top. We manufacture foam mattresses here in the USA.

Hi Jennifer, I have nothing to sell you. I do want to warn you against buying a memory foam mattress. Most are made of toxic chemicals. Those that are plant based and not toxic, are still a slow recovery foam, which sleeps hot and provides inadequate support for a growing body. Sealy makes a line of lower end mattresses that are well made and contain no memory foam. The thinnest of them, that is still good quality, is 8.5" thick. We've recommended this particular mattress for bunk beds and trundles for many years. The Mattress Expert no longer carries Sealy products, but you can buy this mattress at Sears for a very low price. The model name is Lawndale at Sears... It provides good firm support and will last for many years. Pete

I agree with Peter. Memory foam mattresses are not ideal for little ones. They need a little bit firmer support for their growing backs than can be found in most memory foam mattresses at that price point. I would look for any good quality 7-9" thick innerspring mattress with a solid 3" foam encased edge. There are several models by major, name brand, manufacturers that should be easily within your price point. My favorite option here would be a luxury firm Simmons Beautyrest Recharge. Great support and great quality, and a twin at any local store should be in the $350-$450 range. That's what my kids are sleeping on (they are currently 8 years and 6.5 years old). Hope this helps!