Backyard Aquaponics
A place to discuss aquaponics

As I design my next grow bed and fish tank I I thinking of including a solids settling area because when I throw large plants to the fish I have problems with left overs plugging things up. Here is a commercial race. The water comes in at the bottom and moves up while the heavy solids fall down and can be drained off when required. I was thinking of including this into my next fish tank and perhaps into my next grow bed as a way to get rid of the excess plant stems and pieces that would normally just cause problems. I know we depend on the solids and its mineralization to supply nutrients so the goal is not to remove all the solids just the large heavy stuff. I would appreciate any thoughts any of you might have regarding this as well as suggestions. I may be feeding 3 families from this next system so its going to be large enough that I do not want to have to spend time fishing out plant pieces and excess fish poo.

If it is that bad, I would use a spa/pool pump with the big strainer baskets. A lot of the good stuff would get through the mesh, but the big leaves/stalks will get trapped. If that gets blocked too quickly, it is easy to add more in parallel.

Set a screen at 45% over a trough. Pump water to top, water goes through screen into trough, solids move down the screen to be collected. Have to be enclosed to stop algae.
Or build a vortex filter.
With the above commercial system you will loose to much water draining or if you don't do it often enough will end up with either anaerobic situation or breeding aerobic bacteria which feed on detrius.

I don't find netting stems and stuff out that big a problem but I do not like having to clean out the strainer basket on the pump trap all the time. Hence why next time I will definitely have a CHIFT flow to grow bed then pump in sump tank.

TCL

I think a swirl filter may be a better option.

Swirl filter works better if it is in line before a pump. I find mine doesn't really do as well with the pump blended poop smoothie water. Perhaps a slower flow rate would make the swirl filter work better but that won't work for me where I have the thing installed.

or bigger swirl filter. How big is yours TC?

My swirl filter is slightly smaller than a 55 gallon drum. Me thinks the main problem is that the pump has gotten to blend up the solids before they make it to my swirl filter and hence it isn't as effective.

I think the gravel beds make really good ways to catch solids. If one wants to remove even more solids before they get into the gravel, perhaps add a crate, basket or bucket with some bio-degradable fabric that can be pulled out full of solids and fed to the compost or a worm bin. I would make sure whatever container holds the filter fabric can overflow into the grow bed in case the filter fabric gets all clogged up.

My question relates to solids build up.
Ihave been reading today at work that 40% of solids is carbon and therefore I dont think this would be taken up by plant roots as I understand they take up carbon as CO2 through leaves.
Can you tell me how much solids build up. Peopele refer to cleaning their growout beds of sludge. Is this a problem? How much and how often? Does having worms in the beds reduce this?

Worms yes, solids no build up yet none expected,
more than a mature system would be.

carbon is the building block of everything

How Long, is a chinaman, How Much is his cusson
and How Often is his brother

Bacteria will mineralize the plant usable parts of the solids build up and the worms will eat the rest leaving some amount of worm castings which tend to be rich is good microbes to keep the system good and diverse.

Only times you are likely to need to clean "sludge" out of a growbed is if you are feeding all the solids into only one not big enough grow bed for the system. Worms can take care of a lot but if you are dumping a huge load of fish poo into a small bed with only a small population of worms, then that bed will likely get overwhelmed.

I've noticed that one of my beds tends to get more of the solids than some of the other beds. This is probably due to plumbing routing and solids building up in that end of the plumbing. I seem to need to poke that bed's inlet area with a stick far more often than the other beds. After I noticed this, I found some more worms to release into that bed and the buildup hasn't happened again since then.

I do so hate the pump trap getting all clogged up, CHIFT PIST next time definitely.

I use a standard pool pump and sand filter with permabeads replacing the sand. This works really well for solids removal. If you back-wash into gravel beds this material would be digested there. Currently I am settling this stuff and giving it to my worm bin. Extra work, but I don't have a growbed yet, just lots of tilapia in a recirculating system.

BTW- that picture is of a raceway system built by Mike Sipe of cherrysnapper.com, and probably was used without permission by the site you got it from. Mike gets touchy about commercial sites using his work without permission. That system was for intensive tilapia breeding and was a huge raceway system. Air lift pumps were used to move the water. A constant blow-down from a solids filter keeps the water clean. They also used pure oxygen. A constant flow of clean water was provided to make up for losses. Behind the blocks is where the bio filter was.

This seems to be doing the rounds here in Australia... usually from people that have never done any aquaponics... often from staff in hydroponics shops....

I've got no idea who started this "sludge" fest... but as others have replied... it just isn't a problem in well designed flood & drain growbeds... with the appropriate water turnover....

Unless you chronically overfeed, and or run ridiculous stocking densities... in which case you'll have greater problems to worry about than "sludge" in your growbeds ....

More like "sludge" or decaying fish in your fish tank ....



Was going to ask why you filtered the solids out... then back-washed them into the gravel beds??.... until you said you didn't have any growbeds..