Backyard Aquaponics
A place to discuss aquaponics

Hi Bear

There are cone bottom tanks on the market
but I cant find them on the web
I bought this one a few years ago at a clearance auction when the original Hardi went under.


They are used on most agricultural boomsprays for mixing /inductor tanks
you might have more luck ringing a boom spray manufacturer and find
the rotomoulder that makes their tanks.
that one is about 60 Ltr I think. doesn't have a lid just an anti splash rim

Thank you worth ago to check out old farm auctions as well. Cheers

Hi Bear,

I looked through your thread and couldn't find the Radial Flow Filter layout you're using so this suggestion is flying blind but here goes;

I've been looking at improving the RFF on my Recirculating Aquaculture setup and I don't think having the cone bottom will help as much as spreading the flow going out of the tank. What I mean by this is make a manifold or barrier that spreads the flow leaving the tank to reduce the current going to any one location. This will reduce the upward velocity at any given point inside the RFF and keep the solids on the bottom. A good example of this is the v-notch weir in a wastewater treatment plant clarifier. Hopefully this picture link will work - there is a baffle that traps surface scum and then the v-notch weir before the water falls into the gutter to flow out - http://www.staffs.ac.uk/schools/sciences/consultancy/dladmin/zCIWEMWWT/Activity4/Images/PSTcastellatedweir.jpg

You could do the same with your PVC outlet and a donut shaped manifold around the center section of the RFF. Use some flexible pipe with holes all around or even rigid PVC with elbows should do the trick..

Hope this helps. It will be even better with a cone bottom of course (just not sure if that would be as cost effective)

Hi bear and scotty

I'm not to sure how this cone bottom will work, the stilling pipe is going to have to be fairly short. I guess above or level with the start of the cone to get the most reduction in velocity and stop any current stirring up the bottom.
Do you think a castellated bottom on the stilling pipe would also be a good idea so all the flow isn't in one place if
it's not in exactly level? I believe that's the idea of the castellated weir.
Thanks Scotty I was wondering how to make the outflow but I think the idea of the pipe with 45 bends and cuts down the outside with an angle grinder might work pretty well.

Hi bear and scotty

I'm not to sure how this cone bottom will work, the stilling pipe is going to have to be fairly short. I guess above or level with the start of the cone to get the most reduction in velocity and stop any current stirring up the bottom.
Do you think a castellated bottom on the stilling pipe would also be a good idea so all the flow isn't in one place if
it's not in exactly level? I believe that's the idea of the castellated weir.
Thanks Scotty I was wondering how to make the outflow but I think the idea of the pipe with 45 bends and cuts down the outside with an angle grinder might work pretty well.

I've been looking at improving the RFF on my Recirculating Aquaculture setup and I don't think having the cone bottom will help as much as spreading the flow going out of the tank. What I mean by this is make a manifold or barrier that spreads the flow leaving the tank to reduce the current going to any one location. This will reduce the upward velocity at any given point inside the RFF and keep the solids on the bottom. A good example of this is the v-notch weir in a wastewater treatment plant clarifier. Hopefully this picture link will work - there is a baffle that traps surface scum and then the v-notch weir before the water falls into the gutter to flow out - http://www.staffs.ac.uk/schools/science ... edweir.jpg
Exactly right the v notch weir is to reduce weir loading,the coned bottom makes cleaning easy,at 60 degrees a lot of the solids will drop to the base of the cone where removal is at its most efficient,the most solids for the least water.If you have a saw toothed weir in a flat bottom barrel yes it will be more efficient but cleaning is still not as efficient as the weir so your not gaining a lot{new years day and drinking does not give lucid posts sorry]

Johnh, I think you may have better luck just drilling holes along a line in pipe that isn't glued and rotating the holes so they're all at roughly the same level along the top.

I don't know if the notches on the lower part of the stilling pipe are a good idea, they might cause turbulence . Your guess is as good as mine, just try to get it even is what I would do (probably doesn't need to be perfect, just close).



I can see what you mean Andy

HAHAHAHH i just reread that doesn’t make a lot of sense,but it did in my head.....

Goodnight my friends enjoy your new year, after a bottle of red I am heading to bed. Thank you and tomorrow is another day. Cheers

Well then that's all that matters



Cheers Bear

Happy new year bear...

Just a few photos of my filters which I have not posted before.

RFF is just a flat bottom 204 litre (55 USG)

Looking into the drum, up pipe is 65 mm DW

Looking in with pipe surround removed, outlet pipe is 50mm pressure

Chris I presume you are suggesting that I connect a circular pipe to my outlet which goes around the inside of the filter drum so the water is just running through holes drilled in the top of the pipe to minimise waste being dragged in?

The drum sitting on top is the surround drum which sits in the filter. This is 50mm (2 inches) longer than your normal 20 litre (5 USG) drum. Valve at bottom is drain outlet, pipe above is 65mm inlet from fish tanks and pipe on the right hand side is 50 mm pressure out let.

This RFF has had a few modifications so there are extra pipes sticking out which have been capped off.

This filter then runs into another 204 litre drum which has the matala and shade cloth filtration. The water flows in the bottom and out the top then to the moving bio ( C1material).

Showing the support frame and the holes drilled in it to deliver the air for cleaning. I have removed the orange checkered support and the first Matala filter sits directly on the frame.

Showing the different layers, I have not used the coarse matala mat but the next 3 grades with the finest on top. First layer of shade cloth is 30% and second layer is 90%.

This worked very well but may have contributed to the spike in ammonia I just had. Looking at another filter between the RFF and the above filter. One which would collect a lot of the excess waste flowing from the RFF but a simple 10 minute clean each week as part of the normal maintenance schedule.

CC,

Yeah a circular weir that runs around the barrel, connected to your outflow. It reduces water velocity to any one point by spreading the flow. Plus the weirs only let the very top of the water through. Basically screening out any larger floating particles. Here is a good example.
http://www.aquacare.com/products/aquaca ... seperator/

Hey Bear, sorry to hear about your fish loss but great to see how you're soldiering on.