Backyard Aquaponics
A place to discuss aquaponics

I want to get me some Silver Perch but need them to be around the 15 cm mark come next May. This is the catch.... yeah they take two summers to fill your plate etc etc but what sort of growth can I expect over the next 4 months?

I'm thinking 7/8 cm and the SP will double in size come next next late April/May = 15 cm next late April/May but not sure and next input from those higher up lol ... but yeah, what sort of growth can I expect over the next 4 months?

Welcome to the forum KAZ

Hi Kaz, welcome to the forum.

how new is your system and what else have you raised previously ?
what stage are you at with things like cycling ?

SP going in to an established system might get optimum growth but lot of issues potentially arise in a new system/operation.
Older/bigger SP may become an expensive loss for little benefit at larger sizes.

Okay my system is new to me but had a previous owner if that makes sense, it took a couple weeks needing to buy a new pump and get the main tank level - as the main tank is 1/3 into the ground. It's under/inside a future greenhouse but right now just under a pergola type structure - pic below... as for cycling new water (I accidentally knocked seaweed fertilizer into the tank 1 1/2 weeks ago and I had to empty the tank so I could move it/level it up etc last Saturday). I pumped in fresh water Sunday and more yesterday to top it up ...... on the weekend I plan on taking the pH levels and all that ..

That said I think I need some fish to fertilize the bok choy, tomato's and chilli's I got in the grow bed .. we planted them cos my friend had fish but they died on a hot hot day, when their home was being moved ... so ohhhhh well but yeah that's the set up - I might add a second grow bed i the future tho

pic below -tank is dead level, the grow bd is tilted inwards, does my head in lol.. needs fixing ..... ohhhhh nice meeting you both

System will take a bit to settle and cycle. I don't think that getting advanced SP would be viable at such an early stage (some risk of loss IMO) or any real benefit for this summer-autumn.

Suspect you are at least 2 weeks away from being ready for fish, however you could start with just a couple of goldfish/koi initially then look to getting some SP in the new year if any are around. Couple of established goldfish can help SP settle and GF could go in quite soon as they are more robust to system fluctuations and the hot weather that you will experience over next month or so. Plus they will help you to gain experience. Uncoloured goldfish would be fine.

Try Cheidys Backyard Aquaponics in Jandakot when you are ready for SP - they may know who has fish.
Else maybe someone like Woodvale Fish & Lily farm (have stock but cost bit more).
Unlikely you will get a 2017 harvest, and I wouldn't go for anything serious fishwise till after Xmas.
You probably also need to keep stocking to fairly low levels initially in that setup.

get the "new for you but used system". It is the water that is critical.
You may get some benefit from the media if it has been run for some time before, but system will still need a few weeks.

[edit] your water level looks bit high in the pic. Ideally it should be 5cm or so below the top of media.
may be exacerbated if the grow bed is not level.

Getting a goldfish or two might be the go then, son wants one too so we're all winners.

Any advice on my plants, what will ''feed'' them until I get some fish sorted in the new year?

your water testing will still be important as you need to watch pH, ammonia, nitrites and nitrates.
even with a couple of fish you will have to supplement anyway, but it is better than trying to carry too many fish too soon.
You can get 3-5 goldfish no problem.

the best options (and standard recommendations here for Australian AP'ers) are to use Seasol power feed (green bottle), normal Seasol (white bottle) and if needed small amounts of "Blood&Bone with added potash" (Yates etc). Most of this you can get at Bunnings or bigW etc easily.

At this stage you want small amounts of Seasol Power Feed to get the nitrification started.
Power Feed will also provide food (NPK etc ) for the plants, the urea is available for the bacteria
(urea => ammonia => nitrites => nitrates).
Be careful not to add too much Power feed, particularly if you are going to get a couple/few goldfish.
Make up a watering can of the recommended dose and water it over the plants and grow bed.
The bacteria will mainly live in the media in the grow bed. (that is where wastes are broken down to plant food)
Initially do this every few days until you see traces of ammonia in the water tests.
The plants should do fine through this period.

Once you have **ammonia** in the system ease back on Power Feed.
Normal Seasol can then be used once per week as it has much lower levels of Nitrogen and Phosphorous.
You can also use small amounts of Blood&Bone spinkled onto the grow bed - mainly if you have tomatoes.
Bok Choy etc mainly want nitrogen. Try adding some Cos Lettuce as well - they will go well in a new system.

always test water 24 hours (next day) after adding anything. Try not to add to much.

to get a feel for the process you are going through try these two threads...

Petes System - viewtopic.php?f=18&t=27800
* Pete used the power feed method but put too much in initially

PQuigley - viewtopic.php?f=1&t=28000
* Quigs got caught with fish - silver perch - going in a bit too early but appears to have got through.
* good information here about what testing he was doing and what things were important for the fish.

going the few/couple of goldfish route should see you through with much less problems.
and cycling will be done in a few weeks at most.

** as you have a larger fish tank system you may not get very high readings. That is fine as you only need a little bit of ammonia to get things going.

Fish tank looks like 2000 litres I guess (do you know volume) - else measure radius/diameter and depth of water and we can calculate for you.

Ahhh okay that makes sense.

Until now my tomato plant has been going nicely but apart from 3 big red tomatos (the tomatos have deffo turned from small baby green tomatos that they were 3 weeks ago, into what they are now..) .. the plant looks like it's hit the wall and dying a slow death?!!? ........ all I've had is water pumping thur the grow bed but apart from when the seaweed mix was accidentally knocked into the tank the plant (s) have looked rather lifeless imho ........ I will head down to Bunnings tomorrow

ohh it's a 1500 litre tank btw

Yep, as Daz says mature fish can be a gamble in a new system. Although Daz doesn't agree I've found Charlie Carp to be a good supplement. I've not tried PF. B&b yes but my fave is CC.
Pee is also an option however it can take a while to break down into ammonia.
Only 4 months until trout time again and you will grow them out in 6 months.

you can use charlie carp but powerfeed is probably easier and works for the plants as well.
PF gives you good K and the benefits of seasol trace elements.

the urea in PF is probably a pretty good place to be for ammonia as well.

Goldfish added, 3 of the little bastards .. haha

As for the powerfeed, Seasol, blood and bone etc -I had them all bar the b&b - which I do now lol ... I realize it's another question lol but do I continue to;



OR wait until the ammonia increases naturally? Is three goldfish, smallish ones or is 3 small goldfish not gonna be much help when it comes to; ... would using seasol be a no no, you know affect fish in a negative way .. ditto blood and bone .... I have the seasol and blood 'n' bone



Just wonder if I can subsitute the lack of fish poo [until the goldfish are bigger at least], with seasol-powerfeed-blood and bone [obviously done to a routine and with care.. if so] .. or is it just used during cycling your system?

EDIT; I'm sure after re reading that you are using Seasol purely to up the ammonia levels pre adding fish ...... so I just continue adding my mix of Seasol and water in the watering can, checking the pH, Ammonia and Nitrate level daily .... I'm not sure about the Power Feed but I will give it a miss I think ... now I got albeit 3 small fish no need to use Power Feed -same a Blood and Bone .. during cycling the set up only, right?

the goldfish wont be enough and you probably don't want to wait along time
plus they wont be enough to fertilise the plants.

go with the power feed *direct to the plants/grow bed* and check for ammonia initially.
because Powerfeed is urea it will take 24 hours to show up as ammonia so dont put too much in.

the plants and bacteria will live fine on the power feed alone, so better to use small amounts of power feed every few days and creep up on the ammonia. Once it gets to 0.25ppm stop adding PF. Heads up that most people don't see a response and then add too much. Just use a 10L watering can and the recommended dose.

initially the bacteria will feed and establish on any ammonia in the system.
If you add PF then you have ammonia.
plus your little goldfish will add a small bit.


[long term B&B etc] depends on the number of fish and tank levels.
but yes in a new system without many solids the B&B gives you some solids and Seasol / PF helps the plants.
again most important thing is to not use too much. Just need to sprinkle a bit around tomatoes etc.

lettuce and greens will go fine on the seasol / power feed (that already has P anyway).
Tomatoes get a bit hungry..so a bit extra spread over time helps (B&B acts as a slow release).

you should be able to stock up with more fish in the new year anyway.
and when regular tests show low levels or the plants indicate they need something you can add according to what is needed. Your water readings will tell you whether you should be using Seasol (white) or PowerFeed.
Your plants will let you know if they could do with some B&B.

OK mate, thanks for the info ... will update in the future.

oops sorry about the edits - you replied quicker than I typed and fixed the second part

Sweet I'll give that shot, cheers but yes getting some SP in the New Year is the goal but in the short term I just would prefer not to kill my sons pets lol .... I had my friends fish die from the heat/transfer of the set up 2 weeks ago [2 smallish SP and 2 Goldfish..], we have had death in the house prior - once is enough lol .... but honestly I just can't be bothered driving down to replacing them or have to explain why ''Nemo'' is no longer with us lol ..... if trying to explain to him the fact you eat your fish after 12 months [aquaponics in general] didn't go down well, that wouldn't either hahaha