Sorry Aitor,
and thanks for your answer.
Pairs:
            "USDT-BTC": 
                "strategy": "spotGrid",
                "enabled": true,
                "override": 
                    "TRADING_LIMIT": "20",
                    "MIN_VOLUME_TO_SELL": "18",
                    "MIN_VOLUME_TO_BUY": "18"
Market:
        "kraken": {
            "type": "kraken",
            "key": "xxx",
            "secret": "xxx",
            "masterkey": "xxx",
            "mastersecret": "xxx",
            "market": "spot",
            "delay": "10",
            "TRADING_FEES": "1.5",
            "includeCoins": "",
            "filteredBase": "",
            "filteredQuote": "",
            "filteredPair": "",
            "autoPairs": false,
            "pay_with_utility_token": false,
            "tick_interval": 30,
            "isEncrypted": true,
            "tick_time": false
Are those market values correct for Kraken? I found some different values and was not sure ...
Thank you!
Stephan