Backyard Aquaponics
A place to discuss aquaponics

I knew someone would ask me that - I don't know - but here is a picture - anyone's guess as to what it is and whether it will work / is safe?

Update - Still no readings of ammonia, nitrite or nitrate, and very modest growth.
I did however harvest a small lettuce last week and was very excited - but too embaresed to show a photo given others growth!

I have continued to add fish, am am now up to 31 Koi and 4 Murray River Rainbows. I took a couple of photos - the 4 big ones came from my old pond and are a 3-4 years old.

Mike, do you only have the 2 growbeds for 20,000 litres of water?

I missed when you posted about the tears in the liner. Did you wind up using that stuff? I got some "repair" tape for my EPDM liner before, ya gotta make sure the surface is clean and dry before putting the patch on and then let it cure for a day before re-filling. The stuff you showed a picture of kinda looks like double sided stuff for seaming liner? Probably all you need is a patch or single sided patch tape. But I suppose if you have a scrap of liner to put over it you could still use the double sided stuff.

What kind of liner is it? I wouldn't expect a dog to be able to accidentally split EPDM, causing EPDM to leak requires something actually chewing on it or a sharp object being pushed through it.

I didn't end up using the ugly black stuff - couldn't trust it so got some liner tape to join my liner together at the back (have done this bit) and some pond safe glue that can seal even under water which I will use to glue a bit of spare liner on as a patch (will do it this weekend).
I can't believe I am going to say this - but can't remember exactly what the liner was - but good quality rubber from pondsupplies.com.au. It tore where I had cut it to size.

And yep - just the 2 growbeds for 20,000 litres. But being so light on fish for that volume it certainly seems like I couldn't support more growbeds at this stage (ideally I plan to get more later - when the fish all get huge at the least).

Hey guys, I found myself hijacking Burnsy's water turnover thread to ask questions so thought I would post one back here. I am becoming convinced to go back to one of my early plans to have a big biofilter (separate to gravel filled beds) and run my 25,000 ltr/hour pump continously to get the water clear and ensure water quality.

I have heaps of leftover liner, so figure I should just use that as the housing for the biofilter. Not really sure the best way to go about it other than possibly a trench filled with media (balls, jap mats, onion sacks???)?

I figure I should probably pump up to a swirl filter (I have a big blue barrel I could use), then maybe run the outlet into a liner filled trench full of media, before gravity feeding back down to pond.

Anyone got an opinion on size of biofilter, and best way to go?

Maybe koi websites will be a good source of info on the biofilter questions, but I generally find the info on this site more practical!

Sizing of filter depends on application and feeding rates etc. Also what materials you use depends what you want it to do.
If you want to remove solids so they do not get into grow beds then swirl / matting-screen filter / settling chamber,,,,but be prepared to need to clean the matting etc regularly.

If you have a location where you could pump up to what ever you set up and have it waterfall back to the pond, that would be nice.

For ponds, I'm kinda partial to an up flow waterfall type filter. So if you can arrange the liner trench of media in such a location to be the waterfall tank, that would be cool. I would pump the water up and into the bottom of such a trench so the water has to percolate up through the media before it can go over the waterfall. And only bother with a swirl filter or other solids removal if you intend to clean it often!!!! You are probably already going to have to clean the screen or pump trap of leaves regularly.

Neat setup. Really tempting to dive in there on a hot day or slip in with a mask and snorkel and visit the fish.

How about going naturalistic? Make a creek bed, line it, and fill it with several cm of gravel and rock. Will act as a heck of a filter for cleaning. If you line it with more gravel all water will flow subsurface and maximize filtration of algae and other solids as biofilm builds up, but will not oxygenate as well.

On the algae: In order to get rid of the algae one either needs to cut off their sunlight or their nutrients or filter them out or kill them with UV.
>Perhaps some water lilies to cut off light from the water column? Or are you swimming in there? I guess the dogs would make short work of them, so that might not work..
>There are fish-safe dyes (blue-green) that cut off light the algae needs. I don't know if it is safe for us to eat food grown in that water, but should check as it might be great in a swimming pool AP system.
>if you suck enough nutrients out of the water to stop the algae your plants will be small and yellow. Algae are REALLY good at what they do, so that won't work. Dropping PH down to 7.0 or lower will probably help the plants suck more and compete with the algae.
>One can build a UV lighted section of pipe so that any algae going through will get blasted, but that is an extra 50W to 100W....hmm...might be worthwhile just for DW's peace of mind.
>filtering might do it, especially if you have enough filter medium or enough mussels....

Good luck!

Anyone know if Silver Perch and Koi get on in a pond? And whether the silver perch will go OK on the standard Koi pellets. not too worried about growth rates, just healthy fish.

Yep, they'll get along fine... not sure that the koi pellets have enough protein content for the Perch though...

Hey Mike, can give you some pellets when you get the silvers

Quick update and a few photos, finally fond the loud frog I have been looking for the past couple of months - was only an inch long hiding amoungst the irises! Also spotted a few baby koi swimming around today - first breeding in my new pond so excited about that. Will encourage me to try and get my better filter system set up if more fish on the go. Been no movement on the setup for a few months - having a baby and moving into the new house changes the wifes priorities away from the AP setup unfortunately...

Exciting to find baby fish! I, too, find it hard to understand a woman's priorities. How can a baby human be more appealing than baby fish? They can't feed themselves, you have to spend really big bucks on them, and you can't eat 'em. Well, good luck!