What do you mean growing those bitcoins, in any case. Is it in terms of quantity, or in terms of market value. Because in my opinion, the word grow is not the right word for the question you are asking.
But it would be nice if you could use words like "profitable or manage", for the question you made.

Returning to your question, the way bitcoin can increase in terms of market value is due to requests/purchases from bitcoin investors on exchanges.
So if you want to add to the value of the bitcoin assets that you have, the most common way is to trade on the exchange, be it short term, medium term,
or long term. Because according to my personal experience, this is the most effective way to add to the market value of the bitcoin assets that I have. So basically you don't need to think about other things about how to add value to bitcoin assets. Because basically bitcoin is a digital investment asset, the way to make a profit is by trading it. Then regarding risk, all investors in bitcoin must always be prepared for the risks that might be faced. Because if you really want to avoid risk when investing in bitcoin, I don't think you are ready to invest/trade in bitcoin.

Meanwhile, if you want to increase bitcoin assets in terms of quantity, basically you have to increase capital to be able to buy these bitcoins.

But there are, indeed, other alternative ways that can generate bitcoins without using such a large amount of capital. As held by the faucet pay site. On the site, the task is only to be asked to answer puzzles and be paid with bitcoin. But the bitcoin payouts are so small that even if one year of continuing to do the work on the site, the results would be insignificant. So the fastest and surest way to add to the bitcoin assets you have is to just buy them.