health checks on coarse fish.

how many health checks would you do a year,on your fish, if you owned your own commercial fishery??

Maybe every couple of months? (at what cost)?
I don't really know Liam, but no matter how many health checks are made, the fish are still not 100% clear.

Not just regular health checks on the fish but also on water quality and PH levels something often overlooked by fishery owners.

Depends what you mean by health check, and what you would do if you detected a problem.

Most official health checks are carried out to allow fish to be consented to be transferred to another water. For this a sub-sample of 30 need to be killed. If you found, for example, a notifiable parasite, then you wouldn't be able to move any fish out of that water (unless the destination water also had the parasite).

Just keeping an eye on the fish that get caught is often a good enough guide to how well they are growing, if water quality is OK, if parasites are a problem etc. etc.

There is a fact sheet on health checks on the NAFAC website:

http://www.nafac.co.uk/nonmembers/publications/pdfs-04/1904HealthChecks-05.pdf