The fees for each transaction will vary based on the level of congestion on the Bitcoin network at the time, as well as the size of your transaction in kilobytes.
Transaction fees are paid to Bitcoin miners, not to Blockstream.
Note: AQUA uses a technology called “wrapped SegWit,” which typically saves you around 30-40% on fees per transaction compared to Bitcoin wallets that use non-SegWit transactions.
Use the Default Fee Level
If you're looking to save on your transaction fees, just use the default fee level. This requires no extra input on your part, just enter your payment details and tap send as normal.
By default, your application estimates the lowest-possible transaction fee required to have your transaction confirmed within roughly four hours. Due to the unpredictability of the Bitcoin network fee market, sometimes the confirmation may take longer.
Tip: If you need an urgent transaction confirmed faster than four hours, tap Network Fee, and then It's urgent! This will send the transaction with a higher fee, increasing the chances that it gets confirmed sooner.
Another way of saving on your Bitcoin transaction fees is to send bitcoin over the Liquid Network. Transactions on the Liquid Network are generally cheaper than Bitcoin transactions: at the time of writing, the average transaction fee on Liquid is 0.1 satoshi/vbyte, which is one-tenth of the minimum fee on Bitcoin.
Remember to make sure that your recipient supports payments via the Liquid Network!