Backyard Aquaponics
A place to discuss aquaponics

It's a good idea to add the calcium carbonate in a mesh bad so that you can pull it out if the pH goes too high.

Thanks Scotty, was starting with small amounts, will keep in mind for ongoing additions, re purpose wife stockings perhaps.

Things seem to be slow at the moment from a Nitrite conversion perspective, has been a little over 2 weeks since nitrates first showed up but nitrites are yet to fall fast. Ammonia is being chewed up fast, with a quick overnight return to zero when adding a little Charlie Carp, Nitrate levels are falling as plant growth sucks it out, peaked at 160 or so, now down to 5ppm but the Nitrite levels are remaining around the 1-2ppm level.

pH stable currently at ~7.4 after buffering with a combo of Ca/Mg/K carbonates/BiCarbonates and CaOH. Water temps fluctuating in the autumn weather between 11-16C. I guess its just a waiting game now for the slower growing nitrite converting bugs to colonise sufficiently. This weekend temp forecast in the high teens, low 20's so might stimulate a little bacterial growth hopefully.

Was planning on putting in ~12 6-7" trout fingerlings this weekend, but not sure due to the nitrite levels. With Nitrite still around 1-2ppm is this going to be an issue, or should i just wait till the nitrates fall away completely?

Here are some photos: 4.5 weeks since starting the pump and planting out. Some beds appear to be doing better than others.

So 1doz Rainbows were introduced into the system about midday yesterday, all about 6-7".
A couple have started to feed today, taking it slowly a few pellets at a time till they are hitting it well. No fatalities overnight or today, touch wood.

Ammonia, nitrites both @ 0ppm, pH around 7.4, nitrates are up around the 80-160 mark again. Have had a couple of warm days with water temp rising to about 15-16C so its all looking good so far.

I would like to give trout another go they are great fun , used to get my face washed at feeding time , lift the lid enough to throw feed in and plenty water comes out fast .

Don't forget to put the lid back on I lost a couple like that , they jumped out .

Where did you get them , do they have bigger ones , October would be touch and go here for them (water temperature)

I could get a few , not getting much fun out of my Murray Cod they just sit there and ignore me now the water has cooled down .

Hi Terra, got these from Tooperang trout farm at Mount Compass. their fingerlings are all around the 6-7" mark. Don't know if they have any bigger, give them a call.

Looking forward to the feeding activity, kids are also, should be fun!

Trout have been in for 3 days now and have started feeding in earnest. I'm using ~4mm sinking pellets that i bought @ Tooperang when picked up the trout, they were mouthing them a bit so they might be a little big in length. I spent some time breaking them up into smaller pieces as I thought they would go down easier. This mornings feed went well with very little wastage.

Fish starting to rise in the water now to feed but not smashing the surface, give it a couple of days and hopefully they get used to faces above them.

Last night I cut some bird netting I have spare from from fruit tree netting to peg over the tank, that should prevent any losses from jumpers or opportunistic birds as I plan on having the lid open mostly during the day.

Have fashioned a simple siphon vacuum from a piece of conduit heated to flatten one end to approx 6-7mm wide and attached a quick release garden hose fitting on the other, allows a quick vacuum of the FT base to pick up any uneaten food or waste accumulating in the far corners/ibc drain point that the SLO doesn't seem to draw from, this i'm putting into GB's.

It really is amazing how things flourish. Posted a few comparitors below, the first being 6 weeks from first plant out to this morning, with subsequent pics being from week2 vs week6 side by side mostly.

Obvious winners are the Beetroot, Brocolli, Coriander and ornamentals. Chard and spinach seem slower and the Caulis are also slower. A few did get hit by caterpillars so hopefully they will recover.

Lettuce doing well, lost a couple due to mould/rot through the stems close to the clay.



Trout are eating well, starting to hit the surface when fed, surprised my daughter when one came clear of the water and hit the netting over the tank!.

Ammonia and nitrites are steady low @ 0.25 over the past few days so I'll reduce feed a tad till bacteria catch up and get these back to 0 ongoing.

Water temps are sitting around 10-12C due to cold, 6C mornings and 15-16C daytime temps. Heavy dews in the morning leaves lovely droplets on the plants.
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Really enjoying the setup, no major issues so far.

Your doing really well plants look great

With your ammonia don't fall into the same hole I did when I had trout I had 10 fish on 3 growbeds in a new system

I was starving them trying to keep the ammonia down

Do partial water changes so you can keep pouring the feed into them

Unlikely you will keep them past the end of October (water will get too warm)

Grow them as big as you can

Do a search for "nitrate bacteria and temperature"

Interestingly the nitrite bacteria is more COLD tolerant than the nitrate bacteria so not hard to see how with rising ammonia we could find our system in big trouble

Short version is as temperature drops bacteria growth slows

From 25c to 18c growth rate reduces by up to 50% so this doesn't help

At 4c there is no activity

My outdoor system is running from 10 to 18c the last couple of weeks

So our systems capacity in our climate is way different from summer to winter

Over my years on the forum read of many sudden fish losses ive often wondered if this was sometimes the cause

Hi Terra, thanks for the pointers.

I'm keeping a close eye on ammonia/nitrite levels whilst continuing to feed, I concerned about not getting adequate grown before the water warms up. Amm/Nitrite levels still remain very low, just a tinge to the color. Looking at available pH/Temp toxicity charts I seem still to be safe.

I need to do some measurements this weekend to look at average length/weight to see what I "should" be feeding them. At the moment they are getting 3 feeds a day averaging somewhere around 10-12g for the day total (12 trout @ ~15cm average length) in 10C water. Feeding stops when there is no interest in pellets dropped in.

I'm siphoning off a dead spot in the IBC (furthermost corner from SLO immediately under the weakest part of the spray bar) where some waste accumulates every 2-3 days keeping the tank bottom clean, this goes into the GB's under the inflows.

This weekend is sorting out rainwater catchment/storage for topup water. I'm using tap water currently, unfortunately treated with Chloramines, so i'm using an conditioner to neutralise chloramines at recommended dosage.

I need to recheck all pipework/IBC valves for small leaks and standpipe levels to minimise evaporation as I'm adding 60-80L topup every 10-12 days by my records. Not sure if this is usual or I have water loss problem.

I was aware of the temperature dependant bacterial growth, bloody slow buggers compared to the bugs I'm used to dealing with that have generation times of 20-40mins cf. 13-36hrs for these guys! Nitrification is a very poor energy source!

Still, i will remember that I'm only 6 weeks into this and am at the bottom of a steep learning curve. Lots to observe, learn and plan.

After advice on techniques to catch & measure trout with the least amount of stress for the buggers. I've searched the forums but haven't found much at all.

I'm planning on buying a landing net from local tackle store, ideally designed for catch/release, and using a ruler as a simple method doing this at night. Hopefully the fish a less active?

I was also thinking of a large bucket (20L) with some tank water on scales and the measuring weight increase.

Planning on doing this every couple of weeks to track average growth and feed requirements.

Any thoughts, experiences?

The Rubber landing nets are pretty good

Drop the level in the tank (pump into spare tank) to 300mm so you are not hunting them

Ive found with my cod if I put the net in for awhile so they get used to it then gently just block their forward movement they will just drift into net and I can quietly lift them out.

Cunning fish I slowly and quietly drive into net with a broom

I went to a blokes place that was closing down his RAS system to buy some of his fish , he had 5 small tanks and 1 large tank and did lots of sizing his fish.

He had made these gadgets for easy rapid sizing with minimal handling

They were shoe box size with broom handle slatted bottoms so the broom handle lengths were parallel and even spacing he had several of these set at different sizes .

He would scoop up some fish and pour into the box over the top of a fish tank the small ones would slide through and the larger ones would stay in the box and get poured into the next tank

While not much help in the weight of your fish he didn't lose fish using this method as it was quick and efficient

I would go with the pre weighed bucket

Don't do to much of this its pretty stressfull

Picked up one of those rubberised landing nets from BCF on Saturday, used a preweighed bucket and tank water. Caught 5 of the 12 I have, average weight ~65g, length 16cm, biggest 19cm, smallest 14cm. All went Ok with the fish feeding well that afternoon. I'll do this once a month I think, see how it goes.

I like the grading method Terra, something to keep in the back of the mind if I expand

Latest update, now about 10 weeks in. So far the only fatality I've had was a Cauli that had White Rust/Blister Disease, a fungal infection. Pulled that out quick smart to prevent spread! Some plants are looking a bit straggly, putting that down mostly to shading from the brassicas. Plantings for next winter will take plant height into account so will move taller plants to the southern side of the beds to minimise deep winter shading.

Had some wild westerlies as a front came through, pushed some of the larger brassicas over, so I've lashed some garden stakes across the beds and used stocking to tie up/support. The downside of using expanded clay I suppose.

The Doz trout are devouring close to 20g pellets/day now over a morning (me) and late afternoon (kids, when they remember) feed. Unfortunately its dark when I get home most nights, mind you I haven't tried feeding them when dark.......anyone had any experience with nighttime feeds?

As the fish are getting bigger they are obviously moving the water around more as we are not getting any detritus buildup in the IBC corners. The SLO is doing its work as the tank bottom is squeaky clean, except for bio/algae film.

Here are some pics of deep winter. We have been harvesting broccolini, leafy greens, sugar snaps. Have also been shredding brassica leaves for stir fries or as greens for the chickens. Unfortunately they aren't returning the favor as winter laying has stopped . The Caulis have very small heads starting to develop. Looking forward to them!

Looks great! All your plants look really healthy so you must have a green thumb .