Backyard Aquaponics
A place to discuss aquaponics

Hey BuiDoi, thanks for the reply. So you found rhubarb does not like salt? What amount of salt do you run in your system?

God bless, froggo.

Just noticed the post... sorry I missed it...

I had originally salted to three kg per 1kL.. but that has logically dropped with time, and multiple overflows, when I do a top up and get distracted...

I have no idea what the level is now as I don't have a functional measure..
I did buy a refractometer, but foolishly ordered the wrong range (jam making)

I must add some more salt... I'll add that to the todo list...
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I have just about reached my limit for my capacity to cycle the various beds and will very soon, have to implement the semi-automatic flood-n-drain..
the problem is that I had to top up too often..

The lower sump is the source for all flood-n-drain capacity and the pump was getting exposed a bit too often, before I would add another inch or so of top-up water... We know what happens to exposed pumps... they overheat and crack the encapsulation and the end is then on the horizon..

I procrastinated for ages about adding an automatic top-up, but I really did not want to make any holes below water level..

The other day an old toilet cistern appeared on the kerb and thought I, "..I wonder what I could make of that.."



It did not take long to get it screwed to the front of the sump frame



and connected to unused tap, and connect to the Rain Water tank



the challenge came with adjusting the level to a very low level, whereas the system was intended to maintain a high flush level..
To achieve the very low level, I took a second float and glued it to the main one.. ( using Gorilla-Glue )

To keep it vertical, I used an old outer tube for the fill valve... cut down so as to limit the LONG float from going astray..
( had I not just happen to have a similar float, I would have gone for a soda bottle of suitable size )
The interesting trick, is to ensure that the valve opens as much as possible, given the very small pressure..
This was done with a spring.. a large/weak spring from a water level sensor for an old washing machine.. the perfect solution.. the problem is it being steel and thus wont last too long..
( I'll be looking for a SS one, that I am sure to find in some appliance brand )

The main thing is that it works, and will allow me to go away, knowing that I will maintain the absolute correct minimum and maximum water level.. and I have no extra tank holes to fail.. AND - I can disable it via the original tap..
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Well, we have had a serious setback.. I killed all my fish..

35 Silvers.. 6 Salmon.. 16 Trout... RIP

Bottom Line - I suspect that the pump encapsulation crack from overheating, during a LOW WATER event, and this created a slight earth leakage, that became more serious when more salt was added..

Sorry Fish - I didn't mean it..
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damn sorry to hear that

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I have to tell it as it appears..

I DON'T think it was electrocution, despite getting a significant tingle from the salted water.
( More fish died after the affected pump was removed)
I don't think it was cycle values as they have always been near zero..

I don't think it was oxygen as generally, the air boils in the Fish Tanks..
(And having added even more air, those new fish died)

I am now concerned that it was a chemical????? Contamination, that only expensive tests or a CSI lab, would show up..

Last night, I bit the bullet , and drained the complete system, refilling from mains water via two industrial carbon filters....

We now wait to see what happens..
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That toilet cistern doesn't have any chemical residue causing contamination?

Like your tank water level setup,nice out of the box thinking.

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Well, time has passed and sufficient mourning undertaken, after the fish deaths, and meanwhile I set about building a semi-RAS, to give a go to the concept of separating the dramas of keeping fish happy and plants happy..

The new system consists of completely recycled parts, starting with an old Rain-Water tank, cut in half,
Some old olive drums as a cascade swirl filter,
a discarded water tank as a sump,
and on old swimming-pool cartridge filter as final water polishing, before the water returns to the FT via a bio filter..



Exactly half of the original water tank was used and insulation added, the other half will be doctored to secure the normal "Holes" and hopefully it will simply duplicate the FT as shown..
I took blocks of treated pine and made "Wedges" that sat on the ground and the tank sits atop that, giving a concave base to collect and concentrate the detritis..


The filtering consists to twin (serial) swirl filters, that overflow to the Sump Tank, where the pump return any water to the swimming pool cartridge filter and then through that 150mm tube across the back/top.
That tube is stuffed with a wad of bird-netting at either end and some old Bio-Balls from the cichlid days.. in between

The Sump Tank is rather generous at 500L , given that the FT is about 950L..

The plan is to place a part IBC carcase on top of the frame and the "SOME" of the filtered water will flow through clay media, with hardy plants there in to help cut down the final nitrates and thus reduce any water changes..

It has been assembled such that I can play around with the whole show and alter to suit..

So now we cycle for a time and back for another go at getting fish..
Must add.. that I have been astounded at what has come from the swirl filters, given that it was pretty clean water that I started with and no fish etc.
Within 24Hrs, the water is crystal clear and not a grain on the floor of the FT ..

I only hope the new fish don't get the bends from the deep FT..
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Thanks for your thoughts about my dead fish problem, BuiDoi.
I'm guessing you've added fish to your new system by now. What have you stocked and how are they enjoying their new home?
Hopefully your mystery fish killer disappeared with your old system. Kudos for the dunny cistern idea. You seem to have a knack for breathing life into discards and recycles.

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The new system seems to be really great.. super pleased with the results..
Most surprised at the muck coming from the swirl filter, and when you think, that would have typically ended up in a normal. grow bed....

In the NEW (round) system I have about 100 silver perch fingerlings and about five mullet and one Koi..
They all seem happy..

I lost a few over the first weeks, as I had nor really cycled the system, but things have settled.. after I added about 300L of cycled clay as a separate Bio filtration loop
This bed is covered with polyester insulation, and allows 100% wetting and autosiphon draining, whilst preventing light causing algae growth.. the ammonia and nitrates show as near zero, but the nitrites remain a little high.
I do find it odd that ammonia is zero, but nitrites significantly higher..

I have fine tuned the OLD system, by converting to autosiphon, to create significant surges in the FTs.. as these surges are more effective in causing some circulation .. something that is hard to achieve in a cubic tank..
For the past couple of months, I have only had KOI in one of the square / old system, FTs, except that a batch of small. SP fingerlings went in the second tank, when the large ones went into the round system ..
All those small fish died within four days.
Two changes of water later, I now have 15 larger SP in there and they seem to be responding fine..
I can only hope that whatever was in the system and toxic to trout and SP, has now need flushed out..
One flush fill was from filtered tap water and the other from water from the plastic roof..

As part of that fine tuning, I added air stones in the back dark corners, where fish tend to really mass/school..
I speculate that this could be creating a dangerously low DO area.. and this should be helped by the air-stones..
A side benefit seems to be that fish won't school in that boiling water, and thus the fish are forced to spread out more..

So I'm looking at getting more SP for that tank..

So, whilst I'm nervously watching, I am hopeful that the fish killing has stopped .. in that old IBC system..

I am SOOOooo sold on round FTs now that I have lived with one that works.. the fish are always spread out.
Both. Around the floor and vertically in the water column, turning at about once every 90seconds..
IMHO ---- IBCs make great grow beds ..
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.Peter

Glad it is all working out with the new round tanks as FTs. Your descriptions are helpful and informative, thank you for the report

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Truly, the round tank is just sooooooo much better..

I have to be careful about how food is added, lest it all gets sucked from the SLO.. I have to dribble it down the wall, so the current keeps it in suspension longer.

Looking forward to starting the new GB system for the new RAS.. ie. Separating the two processes... just hoping that I can process the wastes fast enough.. yet to be determined ..

Btw.. did I comment that I will not be using rain water from the house roof..
I will never know, but the remaining possibility is that ZINC was the contaminant, and I question whether it actually built up in the clay, and it took many flushes, to be reduced to safer levels..
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Well... here we are, the year has nearly passed.... Both systems are functioning well..

The only slight change.to the slaughter system, is that I have replaced the toilet system auto-fill thingies, with a proper ball-float valve from China.. I did so, as I needed access to the space taken by the toilet system.. I wanted to properly plumb the Supply Tank to the old and new systems..
The old system is just running with about 250 KOI and some yabbies, which are a disappointment.. because they just never work out and you simply end up with a few healthy specimens.. still... they do help process the solids in the ST..
The lounge room aquarium with the breeder yabbies, keeps producing babies to add to the system so they too can be munched.... I'll have to try offloading some Koi as they are getting bigger

Having an oversupply of SP, in the round, I might throw a few small ones into the death system and see if things have changed...
I've tried selling some SP excess , but my price must be too high..

The NEW and round system is working well with a seriously overstocked (about) 150 silvers..

Water chemistry is pretty stable, with near all solids being removed ..
The twin.swirl filter was a small double pain to clear, so I implemented my Washing Machine bowl filter and with a small change, it is working better as far as clearing is concerned..
Whilst the inverse cone worked to a degree, the domed centre gathered too much solids, so a bucket like shape atop the dome concentrated the solids fallout towards the rim..

Like a wiser chap said, filters never work exactly as you expect.. solids gather where you don't anticipate, but I can easily move the remaining, to the tub-sump, in in a few seconds, they are pumped away.. Recognising flow and eddy principles helps with innovation ..
So I am pretty happy with the results..

I have realised that the swimming pool cartridge filter is a pain in application, with clogging causing severe pressure variations, and operational changes.. so I simply filled the canister with small Bio balls.. and in both systems..
It will be interesting to see how they go with cleaning issues.. still, they have other drain ports..

It is interesting how both systems Are performing considering the fish numbers..
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Any pictures?