If youve paid for your miners outright and your making a profit of just under 100 euros a day then isnt that pretty good? If i was making 700 euros a week and didnt even have to do anything to make it then id be pretty happy and certainly wouldnt be turning any miners off at that kind of profit. In fact id be buying more miners if my electricity supply could handle it.
Just to use dollars (since I don't know the denominations in Euros for cents

, lets say he pays 10 cents per KwH for electricity. He's paying $50 per day for power. He WAS getting .23 BTC per day which equals $149.50, giving a profit of $99.50 (lets round to $100). With the halving, he'll now be receiving .115 BTC per day, or $75. Profit = $25.
On a weekly basis, his profit fell from from $700 per week to $175.
And that's only (potentially) a couple difficulty adjustments away from making the return negligible or negative.
And that's the S9, not the early gen S7, which is surely unprofitable to run absent free or nearly free electricity....