Backyard Aquaponics
A place to discuss aquaponics

You do have very nice temps I am sure which should greatly increase microbial activity. The drawback being the oxygen demand it puts on your MTs.. Do you have any way of mesuring ORP in your MT?

Cookie,Swedaquaponics,in my airlift system there was one 60l net filter,this needed cleaning at least twice a week due to the amount of Bio film that developed through the netting,after about four days the film would be covering the top surface of the netting and beginning to go down the outlet.Since expanding the system,i have added another two net filters,one of 60l another of 100l,this Bio film no longer develops,obviously something has changed but for the life of me i can’t see what,on the airlift system turnover is still once per hour,feed rate in this tank is 150g per day,300g for the whole system,the filter system completely unchanged.The net filters now only seem to be catching the fines that make it through the RFFs and not doing anything else,none of the water parameters have changed apart from temp and this has only risen from 22c to 26c,i am confused,at first i thought it was because of the amount of work that was done,large water changes etc,then because it was new netting but after several weeks i am still at a loss as to this change,any ideals...?

ORP... oxidation reduction potential..? lol you begin to sound like my workplace..

@dasboot it seems to me like by increasing the net filters amount you decrease total flow into one filter alone.. so because the filter isn't being loaded as quickly as before.. there is less "food" for the bacteria to develop on at the rate at which it did before.

No the net filter on the DWC system is as was,the two additions are on the other part connected in parallel ,flow through the systems is 1200lph and 2100lph both then connect into the DWCs.

Thanks Cookie, That's great info and a simple system to setup - I'm looking for a source of old bird / fishing net now

You look very happy with those toms, and justifiably so.

Do you pump from the fish tank into the filter via the 1/2" pipe or is that SLO from the FT.

From the FT to filter thru the 1/2" pipe.. that SLO is of the base of the filter itself.

Dasboot, how long has the first net filter been in there for? At what point did you start seeing no need for cleaning it?

The first net filter has been in there for months,its only been in the last month the extension has come on line,i did have flow problems hence the last modifications,now everything is running as it should.My question arises as now the original net filter which needed cleaning bi weekly now only needs cleaning less than once per two weeks.yes it stops the fines coming through,but before when i had copious amounts of bio film i now have none,the same as the other two.
All water parameters are good,as far as i can see the only thing that has changed is the temp,but that is still only risen to 25/26c.....
Bi line, weekly checks on Nitrate has not shown more than 20mgl,so now i have increased the feeding from 200g to 300g to monitor the results.

Sounds like whatever happened is likely to be unrelated to the filter change Andreas. Think about what other things you've changed in the way of pH, nutrient additions, or perhaps cleaning out of solids elsewhere, my best guess anyway

Nice toms Cookie. If you trim off all of the shoots under your first cluster. You will get better airflow, and lower the probability of infestations and bouts with powdery mildew. According to Ryan

Scotty this is why its confusing,everything is as was,the only thing is the addition of the two extra net filters,at first i thought is was because of the amount of work that was done to incorporate both sides to the system, and having to do three 1200l water dumps to modify everything,plus the four tanks were started from scratch,perhaps thats it and i just need give it time,but it has me stumped.
I have just increased the stocking with fifty Tilapia fingerlings and thirty catfish,lets see if that does anything.

i got the same advice from this forum,it worked a treat and by thinning the plant fruit production went up.

Have you come up with an amusing acronym for your system design yet Cookie?
eg
PIFT SIFANT
Pump In Fish Tank Solids In Filter Aerated Netting Tank

All good designers have them

Lol.. Matt!