To be honest, I wouldn't add any further bioload to the 125 litre tank
You are quite overstocked already really given the fish listed in your profile. Is this up to date?
Clown loach in particular are shoaling so 6 needed min and require a tank of 500 litres or more and soft water.
Some of the fish are not really suited either - sorry
Some of these fish need soft, acidic water and some are hardwater more alkaline species - as are the shrimp, to stop their shells dissolving.
Can you post your pH, GH and KH readings at all?
Depending on your water parameters, it may be possible to rehouse/rehome some of the unsuitable fish, giving up more room for more suited stock and the additions you favour
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