How long should I spend draining a CH filter?

[Why Not Indeed]

I have a Spirotech MB3. A mere 6 years after it was installed, I have got around to draining it. The first few buckets were obviously dirty, but now probably 20-30 litres later, it's much clearer [but a bit yellow] with the odd black flake.
The manual suggests 5-10s of draining would be sufficient but not on what schedule.
Should I keep going until it looks like it might be drinkable, or what?

 

[JohnD]

It has a pot that the sediment is supposed to fall into and be trapped. It holds less than a pint. Once you have mostly emptied the contents of the pot, you may as well stop. Drain it again next year and see what it has collected.

IME they do not get the water as clean as a Magnaclean.

What corrosion inhibitor did you add? It will need more now you have drained some out.

 

[Why Not Indeed]

No idea if it had corrosion inhibitor in or not. I don't have any.

 

[fixitflav]

No idea if it had corrosion inhibitor in or not. I don't have any.

In that case, I would add some, quick.

 

[Why Not Indeed]

I did have a look at a few old threads on here about it after reading JohnD's question but concluded that the hive mind was "inconclusive" about how critical it is.
I need to drain the entire system to sort a suspected problem with the diverter valve anyway, so will do it [or at least, think about it some more] after that.

 

[JohnD]

If you're going to drain it, circulate a cleaning chemical such as X400 first, which will loosen the sludge and sediment to help it wash away when you drain the system.

Clean the mud out of the feed and expansion tank first by baling it out into a bucket, to prevent it running down into your pipes and radiators.