Backyard Aquaponics
A place to discuss aquaponics

Thanks, that explains why my system has started to go acidic. Have added some shell grit as a buffer.

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Thanks guys, another 43 degree day and no more deaths. Have just added 200ml HCL (diluted in a bucket and added to waterfall). Will test tomorrow and hopefully have seen some movement, then add more HCL.

How long should I avoid feeding the fish? Poor things got excited every time I walked past!

Feeding them probably will be ok once the pH drops below 8.5.

Or if ammonia drops to zero?

Have been adding 200ml of HCl per day for the past 5 days, ph seems to be coming down a little 8.8 ish?, but ammonia still showing 0.5 or maybe even a bit higher, even without feeding for a week. No more deaths though. Water is looking very murky and starrting to smell as well.

Have added more plants to grow beds to try and suck more nutrients, and am building a series of three pond filters to quickly add some biofiltration. Should be ready to install tomorrow but my bio balls I ordered a week ago aren't here yet unfortunately!

Lets hope that sorts out my problems, if not I have to convince the wife I need 2 more BYAP growbeds sooner than planned...

Why is your ammonia at 0.5 ... and the water "murky and starting to smell".... if you haven't been feeding your fish????

I'd suggest you drag a net along the bottom of the tank to remove anything (possibly dead fish)... and then do a 50% water change....

Add more aeration if you can... and either pump continuously for 24 hours... or adjust your timer to 15 on 30 off.... or even 15/15 if it's really hot...

Something is not right there Mike...

This aint no ordinary aquaponic system Rupe, it looks like Kings Park with a lake. Refer to the pics on page 2 of the thread.
Big scale loi pond and waterfall.

Yeah, just been reviewing the thread... still, with an ammonia reading and water starting to smell... something isn't right...

Given the pond setup, perhaps it's a lot of "litter" on the bottom.... either way, it suggests not enough aeration... and/or water turnover IMO...

+1 for me. I'm thinking there are some dead fish at the bottom of the pond or excess debris.

Thanks for the ideas. Have been pumping the waterfall 24 hr for past week, and today finally had some better readings. I think the murkiness has increased since running the big pump (20,000 ltr/hour) 24 hrs, I suspect it is stirring up the bottom of the pond.
ph down below 8 (I think - always hard to read). Ammonia is still around 0.5 I think, but have started to see nitrite readings for the first time (maybe 0.2?) - could it really only just now be cycling (6 months after filling)?

I have tried digging around the bottom of the pond with a leaf scoop and didn't find too much, but I think I might go in for a swim to check for sure! It's certainly warm enough for it.

Also finished my new bio-filters (put some pictures on shortly) to give it extra filtration so a little more confident today.

Pictures

"Better readings"!

Sediment building up often contains some nasty stuff (ammonia? 'ites? other?). It is good that you are taking care of it before there is enough to kill the fish as has happened to others. Perhaps the smell and ammonia were due to anaerobic decomposition of sediment? Anyway, stirring it up and oxygenating are excellent, almost as good as getting the stuff to suck into a growbed with worms.

I can't imagine that your system was not cycled, but "cycled" means it can cope with a specific steady input of ammonia. The sudden release of more ammonia from sediment, dead critter, or whatever has overwhelmed the bacteria's capability to convert it. They should catch up soon.

Just had a dip in the pond, cleaned up maybe 20 litres of dead leaves, nothing too smelly or decomposed, no dead fish on the bottom. Did manage to find over 20 babies up to 4cm which have bred, and a new batch of 10mm babies too. Must admit it was very nice in there and I spent a good 20 minutes more than I needed to just walking around poking things (not fish).

Maybe its the heat and all the new babies that have pushed the system this past week or so. I am thinking that I may need to start getting rid of some of these fish so my beds can keep up, and/or get more growbeds!

A couple of you experts have mentioned extra filtration / turnover. When I kick in my filtration (hopefully tomorrow if silicone fixes the leak) I will have my 20,000 ltr / hr pump working 24/7 (at least until things are clear again), so that should fix up the turnover. The 3 filter boxes have PVC with holes drilled in them to spray the water onto the filter media, that should help with aeration, but can anyone suggest if I need further, and if so what kind of pump etc would I need for my volume of water? I did look at getting a air pump from BYAP one time but Carl suggested I didn't need one in that volume of water with only 30 fish (now 50), and that the little pumps they had wouldn't really do much to my volume anyway.

As usual any advice greatly appreciated!

What are you using as filter media in your filter boxes Mike...

Being exposed to sunlight, with water splashing onto them... might result in an algael growth on top of the media... can they be covered/shaded??

Csiro's website suggests that paddle aerators are a lot cheaper to run in larger ponds - I don't know if the same would apply in something your size. The noise may be too much in a back yard system but it may be worth investigating. In that size you would need to make your own but I would think the blades out of a material handling fan or blower would be suitable http://www.fanblower.com.au/products/pr ... l.asp?id=4.

Another option worth investigating would be an airlift pump these increase the aeration efficiency of airstones considerably as well as keeping solids in suspension so the circulation pump can take them out.
if you kept the outlet of the airlift below water level (preferably with an elbow on the top to provide more circulation) it would operate very quietly. or you could run the airlifts into your filter boxes right at water level the increased DO will make them run pretty well. Don't have to worry too much about baby fish either - they use airlifts to shift fish in some hatcheries.

A bit about aeration options here http://www.fish.wa.gov.au/docs/aq/aq020/index.php?0300