Backyard Aquaponics
A place to discuss aquaponics

Why would someone want to use a swirl filter for a grow bed only system?

I thought that swirl filters were only necessary for a floating raft system since there are free floating roots that will rot if solids are attached to them, and that solids in a grow bed were a good thing. I can see how it would be a cleaner system for the grow bed, but I also think that it would contribute to a lower nutrient count for the grow bed.

Or am I missing something?

Thanks for your help guys.

Many people are now incorporating solids removal filters into their systems... even if they have grow beds...

This allows them to stock a little higher... if they've taken into account the oxygen requirement... and tank size....

It also lessens the solids loading on the grow beds... prolonging any maintenance requirement...

If doing aquaponics again i would use an aditional filter
After 5 years my beds needed cleaning
My fault i overstocked quite heavy for 2 years

I was chatting with a bloke outside BYAP a few weeks ago and he was building himself a triple filter module, he had thought that he needed it because of the number of people on this very forum who are building external filtration systems. He seemed quite relieved when I said him that a properly stocked system with the right feeding regime doesn't require filtration additional to the GBs; his wife was even happier he didn't have to dedicate more space and $$$.

Too many unprocessed solids in your GB ==> not enough worms in your GB.

Swirl filters and RFF's are a bit of a fad lately. I know where it was all born... its just floated across to here.

There are a variety of reasons for external-to-GB filtering - cleaner GB's is just one of them. A solids filter can offer an opportunity to extend AP systems out to a wider field, such as wicking beds (you don't really want to be dumping solids into the base of them to form anaerobic sludge) or plants beds outside the AP system (mineralise the solids with aeration and you have excellent fertiliser for soil gardens.

Also it might (as in I don't know but it seems logical) allow the nutrient cost of the GB's to be reduced by adding the nutrient-rich water after mineralising directly back into the system.

Another advantage is in small areas - not everyone has a large area for multiple GB's so adding in filtration can increase how many fish they can have without impacting too much on space.

What I would LIKE to have is some gammarus to break the fish poo down even further, unlocking the nutrients that do not get exposed due to being inside the solids particles. I Haven't found a source for them yet... le sigh...

In a properly designed and balanced system with adequate GB's, external filtering, whether bio or solids is not necessary, but it can bring benefits including system resilience as well as allowing dual water systems so parts of the system can be isolated at will by turning a tap.

And as above, it allows higher levels of fish per litre - the more area you have handling wastes the cleaner the water when it returns to the FT, and a couple of barrels will process as much or more than larger GB areas.

Recently put a RRF on my bigger system and am amazed at how much solids it drops out daily. The dirt vegies are loving it

I think EB said it the best in another thread. It's not always about getting rid of the solids completely from the system, its about being more selective on the solids placement/distribution.

I've seen a number of cases on this forum, and experienced it myself, where (even with distribution piping) the area near the GB inlet, or the distribution holes, fill too quickly with gunk.

Making distribution pipes is expensive, 5000 worms are expensive. A cheap RFF to minimize the need for both these things, and a bucket to put the crap where you want. might just be a good economical decisions

The cost of didtribution pipes wouldnt be any more expensive than making/implementing a RFF or swirl filter.... and worms turn up for free if you are patient.

Im still a bit sceptical about the use of one of these filters before media grow beds. If you can only install a small system due to minimal area available but you want to maximise/exceed recommended stocking densities by using one of these filters well your still going to have a large volume of fish in a very small FT... and thats where the problem is. Jam packed fish dont grow well and the reality is they end up tasting like crap... and if your main aim is to get a bulk load of fish, well.. your going to have a bulk load of muddy discusting tasting fish. Wheres the sense in that.


If you incorporate one to use the solids in the garden to diversify the system, well that makes sense.

Unless it's Murray Cod or similar species where lowe stocking density leads to territoriality...

Thanks for reminding me, I want some more murray cod

thanks everyone for your replies. that was some good info.

In my case I have a swirl filter next to my tank to remove the solids from the plumbing. As I will have a few long underground pipe runs it will help to maintain clean lines.

Now that most of the solids are out of the pipes they are just tipped back into the GB every few days by passing the piping.

I will eventually add a pump to the filter to churn the solids up then pump them under pressure into the GB. One or two minutes every day will be all that it needs.

The worms just love it. I think...

Journeyman - re: Gammarus/scuds

http://goliadfarms.com/pages/products/f ... mmarus.htm

US based but you may be able to at least network to something closer.

I disagree. One RFF on a 3-6 bed system would be way cheaper than putting distro pipes around the border of each beds.

And compost worms....how long are you waiting? My first season I ran trout. Not enough worms for that in a new system. iv added probably 500 and still not pleased with the rate they multiply in 750lts of growbed.