The bristlenose needs algae and driftwood.
The electric yellow needs marine based foods and algae.
The peacock needs marine based foods like prawn, fish and squid.
Go to a pet shop and look for a frozen food called "marine mix" or "marine green". These are made from prawn, fish and squid and a bit of algae/ plant matter in the marine green.
If you can't find this, visit a fishing/ bait shop or supermarket and buy some frozen prawn/ shrimp. Keep them in the freezer and take one out, defrost it, remove the head, shell and gut and throw those bits away. Use a pair of scissors to cut the remaining prawn tail into small bits and offer a few bits at a time.
You can buy frozen white bait or blue sardines from bait/ fishing stores too and these can be defrosted and cut up and offered a few bits at a time.
Use flake or pellet foods, and maybe get some frozen brineshrimp and mysis shrimp from the pet shop.
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Feed flake or pellet foods first, then offer the frozen (but defrosted foods). I use to feed dry food in the morning before work and then dry food followed by frozen or live foods after work.
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Monitor water quality when feeding meat based foods because they can cause ammonia and nitrite spikes when first used.
Do regular water changes and gravel cleans to help keep the water clean.