Backyard Aquaponics
A place to discuss aquaponics

Hi all,long time reader first time poster.
I have set up my first system comprising one 2500L tank and three bath tubs as grow beds.
The system has been running for almost 4 weeks and about 2 weeks ago I added 20 silver perch of which
we have 18 remaining . They are all around 50mm in length and other than being quite reclusive, appear to
be happy enough.
I have a few questions if any of you wise folk out there have the inclination to answer. Atm I can't really tell if the fish are eating. I feed them about two large table spoons of food at around 6.30am and have never seen them eat it and appear to have a fair amount on bottom of tank where I feed them. Also my vegies although quite healthy don't seem to be doing very much. So my questions are 1) how do I know my fish are eating and going to be ok and 2) is there anything I could/should safely add to the tank to help my vegies along ? Any feedback would be appreciated ,thanks.

Way too much feed "mmgog"... not sure what size pellet you're using... but two teaspoons per day... (one teaspoon, twice daily)... would probably be enough....

Silver Perch wont really eat well if the water temp is below 18 degrees... so they probably wont eat if feeding early morning when temps are down ....

Make their main feed about an hour before sunset...

You should never have uneaten feed remaining on the bottom of the tank the next morning...

If you do.... remove it... otherwise it will decompose and raise ammonia...





Yep add a capful of seasol per week....

By the way... do you have a test kit??

hi mmgog
we both have very similar systems (click on my link below)
I also started with 20 SP and now down to 18.
When I feed them close to sunset they come up and attack the pellets with gusto. I am using 3mm floating pellets from the BYAP shop. When it is sunny or if you are standing right over the tank they can get a bit shy.

Hi, thanks for the replies. Rupert the fish feed I'm using is really tiny stuff probably less than one mm in diameter that I got from the fish supplier. I have a master test kit and used to test like crazy but other than a very tiny rise in amm to 0.25 for a couple or days in week two all readings have been zero but ill test today and post later. I'll also change the feed time and see, thanks for the suggestion.
Hi gorutsuki69 I think I was a little naive about my large pump.and small fish so imagine my dismay upon finding a fish in my gb and another under my filter. Had I put mesh over pump earlier I'm sure I would still have 20.
Your system looks great, except for that menacing looking bird, cheeky little bugger.

Silver Perch are also very reactive to barometric pressure change.... an approaching cold front will put them off their feed... usually sending them skulking to the bottom of the tank...

Once the front arrives... they resume feeding well....

Hi mmgog,

I too have a system that is similar in age to your self and am currently running 30 silvers. My readings also sound the same with only a very slight raise in the level of ammonia (either that or I have convinced myself that the colour is turning a slight green shade).

I am not feeding very much, a bit before work in the morning then giving them a fair amount (teaspoon) in the afternoon. I place the food down near the pump where they tend to hide out and when I come back and check it all appears to be gone. To my knowledge all my silvers are still alive though it is a bit hard to see as the water is greening a bit.

I add a capful of seasol once per week and will go and get some chelated iron today and give that once per month.

I also have a number of goldfish in the tank and this seems to help with any clean-up issues in the tank. I have more than I currently need about 10 and am happy to reduce this by half if you want some. I too live in Bunbury so let me know if you want to come over and grab a few.

As Rupert said, I would definitely cut back on the feed for a while till it heats up and you can add more size to your fish.

Your feed may be going up the pump....?

If your water is starting to turn green I'd stop feeding or cut it to an absolute minimum, and stop adding things to the system for a while.

Good call, should I leave it till the green disappears or just give it a few days (or should the process clear up in a few days)?

Give it a while, might take a week or two.... Or three......

Todays test were pretty much the same as usual PH 7.8,Ni 0,Na 0 and amm appears to be somewhere between 0 and0.25. I moved feed time to late this arvo as suggested and was privileged enough to spot a couple fish come and have a feed.I also added a capful of seasol as suggested.
Cheers for the goldy offer Borby I'm trying my best to be patient at the moment so ill see if I can keep the little fellas I've got going for now. Can I ask where you got your sp's from?

Got my silvers from Gavin out in Ferguson.

Just had a good look at my water and can see the bottom, had shade cloth over it and it was making it greener looking than I thought. From what I have read on my instructions from BYAP it is a stage that it will go through.

Fed the silvers and they all came out for a good feed. Will stick to the once per day for the eight weeks unless the situation changes!

Hmmm not quite sure what's going on with my testing. This morning I tested the water PH was about 8 amm 0-0.25 nitrite 0 and nitrate 20. I was excited to finally see some movement in the readings. I got distracted and let my nitrate sample sit for a few minutes and noticed it seemed to get considerably darker to read 40 possibly 80 ppm. I thought I would do a test tonight and let them all sit to see if they changed. Initial results as follows:
PH 7.8
Amm 0.25
Nitrate 0
Nitrate 5
I let the samples all sit for a few minutes and amm sample seems to be 0 now and the nitrite sample has gone to 2 (finding it hard to differentiate between the shades of purple) I think. Questions are 1 are you supposed to let all samples sit for a while 2 is this the spike I've been waiting for and 3 would it be wise to salt the tank,if so how much do you think for 2500 L ?

Read the instructions. All but the pH tests are supposed to sit for 5 minutes before reading. High nitrate isn't much to worry about though. Ammonia and nitrite are the ones to watch.

testing at different times of the day will make some difference as well... so pick a "regular" time for tests