Please see the image below.
The fish are kept outside. Water parameters are all fine except nitrate a little high at 40 mg/l. (The nitrates in London tap water are so high that water changes will not help!). It is not possible to buy antibiotics over the counter in the UK. I have been recommended a product called "eSHa 2000" but I can see it has copper in it, and I really don't want to destroy the biological filter and cause even more distress to the fish with ammonia and nitrite spikes. Please let me know what you think!
Will the salt harm aquatic plants? (***** *****lies, oxygenators, marginals)
Thanks for your help. I got both medications today so fingers crossed!
One more question, the oldest of the fish is very bloated and has a couple of lumps. He seems happy and eats well, but is getting progressively more misshapen. Is there anything I can do? I have attached a pic below.