I have a Chop 2 system running for about 18 months and is been working great but lately I have to add chelated iron to keep the ph around 7 if not it drops to PH 5. I have to do this every 3 or 4 weeks. Is this normal for a stablished system.
My system is made of 3 grow beds (about 100 gallons each), a 100 gallon sump and the size of my fish tank is about 300 gallons. I have around 60 tilapias around 6" average. I have air pumps running in the fish tank and I do have plants in all the grow beds. I added worms yesterday in the growbeds hopefully to keep my growbeds more healthy.
That would make sense, I have a 100 gallon rubbermaid tank that I use as a raft bed. I wonder if I can re route the water from the fish tank and dump it on the raft bed tank and from the raft bed to the sump where my pump is located, that way I can use the raft bed as a settling tank. The raft bed tank has a drain on the bottom that I can use it to get rid of the solids when need to. I'm just not sure if this setup can hurt my raft bed plants.
I added a short video clip and pics of the swirl filter that is on our system. You can find them on my page It is a round flexible plastic container with about a 12 to 14 gal capacity.
thanks for the video and pictures....I have to work on this project this weekend
Raft beds will certainly tend to settle solids out. However, you want to be very cautious about sending much excess solids into a raft bed since an abundance of solids in a raft bed can cause quite a lot of trouble for the plants if the solids manage to cling to the roots of the plants. And if a thick layer of solids builds up in the bottom and then floats up to the plant roots it can really do a number on the plants.
Much of these warning will depend greatly on the scale of the solids issue. Keep in mind that large amounts of solids will increase the Biological oxygen demand in a system and they can use up available dissolved oxygen quickly. However if you are dealing with really low densities and not much solids, you can get away with alot.
The raft bed is doing so good I really don't want to take a chance, So I decided to go with the parts I had available and ended up making a "Fresh flow solids filter" out of a 55 gallon barrel based on this youtube video:http://www.youtube.com/watch?v=6iNpDsxV-aE . I can't believe how much solids it collected in 24 hours. The bottom of the barrel is covered with solids.
Paul knows his stuff... and the design is so simple to implement