Backyard Aquaponics
A place to discuss aquaponics

I don't have a DWC bed but I can't help to think that filtering out very small particles may be a little over the top for backyard DIY purposes… I think getting rid of the larger stuff with the RFF and the some more in the MT is worthwhile but I don't think a little bit of fine particles in your DWC is going to hurt your growth that much or result in a need to clean it often.
I base this on the fact that my flooded sort-of NFT pipes get some fine build up on the bottom of the inside of the pipe and the roots of my lettuce is still white and clean and the growth is good… I think in DWC beds that are much deeper than my pipes the particles would settle on the bottom away from the roots so even less of a problem.
I also think that aeration the DWC bed would be far more important than the fine particle filter…
But I am just guessing so feel free to shoot me down everyone

tom77 we have a similar set up with the same results,i have a swirl filter then on to a shade cloth filled 60litre barrel,slight deposit in the bottom of the tubes but growth good,white roots so i didn’t bother to filter anymore. I am in the process of changing the tubes over to DWC and i shall utilise the same filtration layout,maybe add another small barrel with Bio Balls, then onto the shade cloth.

Do you have to clean the shadecloth often?
I have 2 biofilters in my sumps, 25L of K1 media in each, I was originally going to use bio balls but from what I gathered the K1 media is better because of its self cleaning abilities and higher SSA

K1 is only self cleaning in a properly setup moving bed filter, otherwise it is just expensive plastic "rocks".

yep but that means an air stone with adequate flow... so a barrel with an air stone, not rocket science. And even if not setup exactly right they still have a high SSA and would be doing what a grow bed would do in smaller area.. ofcourse to get the maximum benefit there has to be a high level of oxygenation for the bacteria.

yea of coarse, i was just making it clear that they are not self cleaning in your sump, so others dont think they are "magic balls" that are actually self cleaning.....

Yes I agree, I probably should have pointed out that in my system they are in plastic laundry baskets suspended in the sumps and I use the water flow from the GBs above to splash into the baskets... I have yet to add the extra air pump i need for it to function properly but it is on the list 'to do'... the sumps are a good place to have them though as I have little space and 3 sumps that otherwise just act as water reserves.

Cleaning is now is two weekly,the flow is spread over the bottom of the barrel,so on two weeks there is a healthy layer of slime,but it doesn’t visible effect flow of nitrate.
Not worried about the BSA this is purely mechanical.