Backyard Aquaponics
A place to discuss aquaponics

They are pretty good for biological filtration but in a BYAP system there is generally such an abundance of biofiltration capacity that you really don't have to consider it at all.

If you were running a split loop system then maybe but even people who are adding all sorts of unnecessary extras for solids removal have no need for extra bio-filtration.

Thanks, I'm going to go with a RFF I just have to figure out how the flow rate is gonna work.

Why?

That would depend on the level of the standpipe to the level of the water in the FT. Water always flows to the lowest point.

Will it eventually level out to the level of the Fish Tank or level out to the top of the stand pipe? Also not to mention what size pipes i will use so that the pump does not empty the water faster than it flows in. I'm looking at adding two 16 Gallon barrels to the left of my IBC tank, the furthest to the left would be the RFF , it would then flow into the closest one to the IBC that would be my sump. So you see i'm wondering how high would the water rise in the barrels, would it level out so that the fish tank and the barrel are at equal water heights or would it stop at the top of the standpipe even though its lower then the IBC water height. Im also wondering what size pipe i would need if i wanted my 850 GPH pump to run constantly in the Sump barrel because if the sump barrel runs out of water id ruin my pump. The Fish Tank is 250 Gallons. Im a newb at this but just gotta figure this out.

If you drain water from the bottom of the FT (IBC), the water in other tanks will rise to the height of the FT. In other words, if your other barrels and standpipes are lower than the water level in the FT, they will overflow until the FT is drained to the same level.

It is MUCH better to use an overflow type drain in the FT. That way, water will only leave the FT when it overflows into a standpipe or SLO type drain. Once it drops below that level water can no longer leave the FT. In that way, the downstream barrels can be lower than the FT and they MAY not overflow, depending on how much water is needed to fill your grow beds.

An example: 275 gallon fish tank (FT) that drains by an overflow. The tank will always have 275 gallons, unless it starts to fill due to draining grow beds (GB). Then it overflows into the drain and supplies the next barrel with water (RFF?). That barrel will fill until the water level reaches it's overflow and then start to fill the sump tank (ST).

The pump will remove water from the ST to supply the GBs. In your exampe I think you mention a 16 gallon sump tank. This sounds very small to me for the following reasons. You never want the pump to run dry, so assume that you always need at least 5 gallons in the ST. That leaves 11 gallons of water, IF all barrels are full (FT, RFF, ST) AND there is no evaporation or loss, etc. That means you only have 11 gallons (if the sump is FULL TO OVERFLOWING) to fill your growbeds. 11 gallons to fill GBs is maybe only 25 gallons of GB, and is not enough to support a 275 gal FT with a reasonable number of fish.

Here's what you need: A ST big enough to hold ALL the water from your GBs when the pump is off PLUS the minimum water required to keep the pump wet PLUS the cushion you want to allow for evaporation and losses between topping off the water level. Will you replentish daily, weekly, monthly? When the pump turns off (planned or otherwise) and ALL the water drains from the GBs, where will it go? Does your sump have enough volume to capture it all? When the pump is ON and all the GBs are full at the same time, is there enough water available to keep the pump running (wet)?

Keep in mind that a 50 gallon GB with media requires much less than 50 gallons to fill because of the media. How much less depends on the fill height, the media used, etc.

Hi
This has got a bit confusing so lets go back to first principles.
20 tilapia should require about 400 ltrs of wet media. River rock, clay balls or bottle tops. Whatever.
If you have that much media it will provide sufficient bio-filtration and you do not need additional filters.
However if you want to increase fish capacity or simply tinker.
An RFF and a sump tank is probably the way to go.
Many designs on here for RFF.

Now I could sell you a double hydrostatic self charging Nano particle twin drum 11 Micron rotating flux capacitor filter , but I haven’t got the patent yet!

RFF is good!
Think of it as removing the big bits!
Sump tank; as big as possible
Move your pump to the sump.
Your next challenge is the SLO, solids lift overflow
Fancy name for a pipe running along the bottom of you FT. Slits cut in it lift solids .
Cut a hole in your FT at the maximum height you want the water. No Not there! The bottom of the pipe! This flows into your RFF and then onto your sump. Gravity.
You will need to empty and clean your RFF regularly but it is great for soil gardens.
The bottom of the hole you cut in the FT will determine the height of water in the FT.
The RFF outlet should flow onto your sump tank
It’s not rocket science; It’s fluid dynamics!
Works for me!

LOL. Rcoket science IS fluid dynamics.

When you put your hand in front of a jet of water you can feel the the force of the water. There is a corresponding opposite force on the nozzle or pipe from where the jet of water originates.

You almost got me there!
But Nah!
Rocket science is..... Science, 2+2 = 4 DOH!
Fluid dynamics is;
The perfect head on a glass of beer!
The Fizz when you open a bottle of champagne.
2 +2 = bliss
Mathematics plus!
The 1984 cry of , “I am not a number”
Have a cold one on me!

Anything can be used as a filter but how they are cleaned is the key.
RFF, swirl and settling tanks are simple to flush out but only "filter" heavy materials - pretty good compromise

Other media will need flushing or washing, burning time, water and energy. Make sure there is a plan for water flow if they clog up.
I have swirl then a K1 fixed media filter, water in the bottom out the top. Can flush media using low pressure air, fish miss out for a little while, let settle then drain.

Got to hand it to you Titus perfect explanation ..... : And i want a pint of what ever your drinking...

If you have an ibc have a look at my chift Pist system I built it has sump and slo it's working fine hope this will help

..
I beg to differ..

My suspicion is that in a smaller system, a mechanical filter IS beneficial..
I base this on my use of a cartridge filter, that provides clear water but does not congest..
Ie... the filtered material vanishes ...

I extend this thought to sand and assume that they will react similarly..
Ie.. the pressure of highly oxygenated water flow, will cause near complete mineralisation of solids..

Would I use a sand filter.. no...
A cartridge is easily removed and cleaned if thought necessary.. that is a safeguard..

My only thought, then, is when would that filter become a problem.... when the amount of solids reduced flow to the point of anaerobic response ..
When would I suspect that state...? ... When the pressure rose, as in a normal swimming pool application..

I read warnings about filters, but thus far, I have not seen the predictions... I am now actively seeking canister filters, IN CASE. I want more..
..
.
.

Cannister filters seem like they may be expencive and short term.