Recently I was helping my daughter with her bank account and noticed a $1 withdrawal labeled “Stash Fee”. It was a fee to robo-adviser, Stash. Normally I would be thrilled by the good news that my daughter was saving and investing. But in this case I wasn’t.

I had a couple of concerns, but the biggest one was that $1 fee which would be coming out of her account monthly as long as she maintained her account with Stash. It doesn’t seem like a lot, $12 per year, but she had only invested $50 so far. That’s an investment expense of two percent per month! It would be really hard for her investment to make money with that expense load.

I’m a fan of robo-advisers. They offer a great service for savers with both small balances and big ones. They generally use low cost exchange traded funds to build a well diversified portfolio, and their management fees are also low. For more details on robo-advisers, check out the post I did a little over a year ago.

The Stash service allows investors to invest as little as $5.00. You can set up an automatic regular transfer from your bank account. In fact, you are required to link your bank account to your Stash account, so they can automatically withdraw your fees every month.

Most robo-advisers subtract your fees from your investment account, and even with small balances, the fees are lower. Betterment, and Wealthfront two other robo-advisers, offer investment management for 0.25 percent per year. Betterment has no minimum balance, but Wealthfront does require an initial $500 investment.

Stash bills itself as a way for young investors to learn more about investments while building their portfolio. They offer lots of information on investing as well as help selecting investments. But they seem to leave out the bit about how high fees eat into your savings.

Stash’s fees do become more reasonable as a percent of your investments the more you invest. Once your balance hits $5,000, the fee converts to 0.25 percent per year, which is about $12.50 on that amount of money. That is in line with Betterment and Wealthfront, but both those advisers will build your portfolio for you, as opposed to offering to help you build your own.

This experience highlights the importance of understanding what you are getting into. Never hand over your money to any adviser without investigating how they work, what they offer and how they compare to other alternatives. There are many low cost ways to have your money invested for you.

Robo-advisers are a good way to go, particularly if you don’t have much to invest right away. However, Stash’s fee structure makes them a poor choice for balances less than a few thousand dollars. There are other options with much lower fees. If you like what Stash has to offer, wait until you’ve saved up the $5,000 to make the fees competitive before you invest with them. Whatever investment adviser you choose, make sure that you understand what they offer and what they charge before you hand over your money.