Backyard Aquaponics
A place to discuss aquaponics

Yep I agree, problem is that the pool was a bit too green before even starting so I want to get it under control before stocking up. Too much and it will just take away the nutrients from the plants plus apparently the O2 levels can drop drastically overnight if there is too much algae. Probably not a problem with only 20 fish in 40,000L but I want it at a reasonable level before I start adding too many more. I probably should have killed it all off before putting the fish in but I didn't know what after affects there would be if I chucked in algaecide and I wanted to let the system settle long enough for any chlorine to dissipate.

I'm getting the UV unit, and advice, from a professional fish breeder who also grows aquarium plans for a living so presumably he knows a little bit about it. His view is that the algae is steeling the nutrients and while the UV may kill bacteria the important stuff is concentrated in the grow beads/filter so the damage should be limited. Also the idea is not to run it permanently. I can probably also get a buyer for the UV unit once things have stabilised so I am not too worried about the UV cost.

Still like the entire exercise this is all a learning experience, I may not be doing the best thing but like everyone else here at least I'm doing something.

I have a shade sail which I have taken down over winter and will put back up in summer. It puts a bit too much of a shadow over the GB's to leave up at the moment.

looks like you have your bases covered mate
what you say makes sense to me.

Good to hear

Are you planning on/hoping to swim in the pool as well?
If no - why are you using a UV filter at all?
If yes - I'm guessing you could get away with using it mostly over summer only. That way there's plenty of time for the bacteria to colonise the growbeds, and then the bacteria will stay there and not be affected by the UV.
I'm interested in what your friend has to say, and the type/size/flow rate of the UV filter (I have a 60K litre pool to convert in about a year and a half)

According to the write-ups on the UV steriliser they should not affect the bacteria, they only kill the mobile algae and diseases in the water. He uses a 9w UV filter in his large tank (20,000L) and it clears the algae in about a week. After that he switches it off and only uses it when he develops an algae problem again. Normally he only needs it about once a year at most, his tank however is covered from direct sunlight.

He recommends an 18w UV steriliser and thinks it will take about 2 weeks max to clear. He didn't say anything about flow rate but I will ask he when he delivers it. I was planning on using a spare 2800L/h pond pump with a fountain attachment to give a bit extra aeration.

No I am not planning on swimming in the pool.

The idea is to clear the algae so that all the nutrients can go to establishing the GB's. Once it's clear then I'll switch off/remove the UV unit. The unit is going to cost me $200 for a poolmaster 18W.

As promised here are some pictures.

The Green Pool


Trout in 1000l tank


Trout about to have a feed of guppy

1000L tank and GB's


Few GB pics

Couple more pics

Mint loves AP

Finaly a couple of shots of the trout

thanks for the pics.... fish look healthy

very cool looking stuff....keep the pic'S rolling..rolling...rolling ( there is no drumb bass icon..soo IMAGINE )

My fav's the one with the guppy legging it

JP pool looks a lot different to the pic you posted on the other page , small system is looking good, you're right mint loves AP but it can take over and keep coming back, pic below is 8 weeks of mint grown in the missus's bathtub system with a sink GB

I knew mint could be a problem in a garden but though with the loose medium in a GB it would be reasonably easy to control. Think I might be removing the mint....


Yep the pool changes colour fairly quickly once the chlorinator got switch off and the salt levels dropped.

I would take it out JP, but does keep coming back, you never get all the roots