newbie aquaponics filter ?'s

hello everyone,
i am gathering my knowledge and supplies to start a indoor aquapoincs system. i plan on doing at least 1 275 gallon IBC tote setup. i will have perch or tilapia in the tote, crayfish in the raft beds. i will also use the ebb and flow setup with the lid, pvc for vertical growth and plan on trying to grow duck weed for the fish or chickens (probably in some recycled gutters). this system will be of modular design and will be completed in steps rather then all at once.

so that is likely enough filtration with all the plants but i figure i can have a denser population and more buffer with a filter.  thinking one or more 55 gallon drums filled with a media for the bacteria.
on to the questions;
1) adding a barrel as a filter count toward total gallons when stocking fish? ie. i have 250 gallons in my tote and 20 more gallons in my raft beds and 40 gallons in my filter barrel, is that 310 gallons towards fish stocking?
2)media for filter, being an organic soil grower and all about reusing things, i thought if i could use crushed (not to powder,lol) lava rock, growstones, biochar, coco coir, etc i could then remove most (want to keep some in for the microbes colony) and add to my soil mixes and/or compost/vermicompost when it gets gunked up. anyone try this? what works best?

not a filter question but anyways,
i was thinking of using a 55 gallon drum for hatchlings/ small fry and connecting into the whole system, would that work or will the fry outgrow it too fast?

my end goal is fresh healthy food for my family and i, and all the "waste" is actually getting used to grow more food. cheap, eco-friendly, sustainable, and multi-purpose.

Brad Kay wrote:
1) adding a barrel as a filter count toward total gallons when stocking fish? ie. i have 250 gallons in my tote and 20 more gallons in my raft beds and 40 gallons in my filter barrel, is that 310 gallons towards fish stocking?

Any filtration counts towards the fish stocking density. First off, right after your fish tank you need a settling filter. They are called swirl filter or radial flow filter. This mechanical (medialess) filter works with gravity to remove fish feces and uneaten food that can sink to the bottom.

The second kind of filter is the Moving Bed Bio Reactor. Water enters from the bottom, aeration goes full steam and some sort of plastic media with high surface area is home to bacteria that converts ammonia to nitrite. Hobby systems use bottle caps but if you have the finances Kaldes K1 or similar would be the choice.

Brad Kay wrote:
2)media for filter, being an organic soil grower and all about reusing things, i thought if i could use crushed (not to powder,lol) lava rock, growstones, biochar, coco coir, etc i could then remove most (want to keep some in for the microbes colony) and add to my soil mixes and/or compost/vermicompost when it gets gunked up. anyone try this? what works best?

If it is a trickle filter where water slowly trickles on things like mussel or oyster shells, rocks, bio-balls, it may work.  This is a different kind of filter.

I only have a settling filter and from there it goes into media beds where I grow plants. I am using scoria which is a volcanic rock with high surface area.

Any rock you want to use, first test them in vinegar, if they bubble, they are not good to use in aquaponics as they can alter the pH drastically.

Brad Kay wrote:
not a filter question but anyways,
i was thinking of using a 55 gallon drum for hatchlings/ small fry and connecting into the whole system, would that work or will the fry outgrow it too fast?  

Yes, it will work. you need properly sized catchers so the fry can not get out of the tank into the pipes and pumps.

Have a read of my system if you haven't already. I explained the components in detail. Here is the definition of my current system.

Brad Kay wrote:hello everyone,
2)media for filter, being an organic soil grower and all about reusing things, i thought if i could use crushed (not to powder,lol) lava rock, growstones, biochar, coco coir, etc i could then remove most (want to keep some in for the microbes colony) and add to my soil mixes and/or compost/vermicompost when it gets gunked up. anyone try this? what works best?

Lava rock is very similar to expanded clay- Biochar I would be worried about how ash raises pH- coco coir as long as it doesn't wash out of your grow bed should be fine