Backyard Aquaponics
A place to discuss aquaponics

Ah yes, sulphate. Not carbonate. I never did like chemistry...

Just checked the temperature in the sump (late afternoon, has been a stinking hot day) and it was about 28-29 deg C. Was perhaps 0.5 to 1 degree cooler in on of the upper ponds.

150g of "pH down" has brought the pH of the system down to 7.4 (from readings of about 7.6-7.. I think I'll give it the same dose again.

Added 2.7kg of Sunray Pool Salt to the system yesterday evening (about 1 ppt added).

Ammonia still sitting on 0.25 ppm, temp ~ 23.5 deg C, no nitrite but a possible small (2.5ppm) nitrate reading.

If we get another heatwave and water temps get near 29-30 deg again, as long as I've got the pH down to around 7 then we should be out of the woods with respect to ammonia toxicity. The salt should help with fish health as well.

We're down to (at the most) 3 goldfish - can only see 1 but it looks really happy.

This morning's job is to install air stones in the sump.

Hold off on anymore pH down James... or anything else for that matter... your readings are fine... and I think your system just needs to catch up and stabilise for a while...

Fish might enjoy a day or two of respite as well.... you've got the salt in there... so every thing should be fine..

i agree with rupert you have changed your ph by ~1 and the fish need a break

i normally only lose a goldfish or 2 if my system ph swings around..... the longer it does, it the more fish i lose

currently running with 25 - 30 degrees c and ammonia .25 , nitrite 0, nitrate about 5 to 10
with a system ph of about6.8 - 7.2 ( depending on how much tap water i add to the system ) my tap water is over 8.6 so i use it a bit like ph down when i do a water change or top up i really need to start collecting rain water for top ups so my system is more stable

my 2c

Darn, should have checked on here. Now I've already added another 150g of pH down, which should take the system down to 7.0 - 7.2 ...

Added an aerator (one with a battery backup that came from Dad's system) to the sump - it's creating loads and loads of bubbles via two 30cm airstones. At this stage, we're relying on the other ponds remaining oxygenated from all the splashing and from the aquatic plants.

Splashed out (sorry, bad pun) and bought another 10 goldfish - my local aquarium shop guy has taken an interest in the concept and gave me a discount - so we'll sit tight on these and see what happens. They'll have pretty much ideal conditions now - nice temperature, near-neutral pH, plenty of oxygen.

Hoping to test the water for zinc tomorrow...

Thank goodness for cool changes.

Water Temp 19 deg C
pH 7.2
NH3 0.25 ppm
NO2 0
NO3 >0 but <5 ppm

As far as I can see, all 10 goldfish bought yesterday are swimming around, and feeding. I think this is a VERY good sign!

Hopefully Zinc test will be taking place Tuesday with Atomic Absorption Spectrophotometer

Damn... never thought about that... I've got one hanging around in the cupboard somewhere too....

Yes i keep mine in the cutlery draw. You never know when you may need an Atomic Absorption Spectrophotometer or a whisk.

Your cutlery draw must be a little bigger than mine
Look forward to seeing the results. I collect much of my AP water from a "tin" roof.
Nice looking setup BTW....

I keep mine under the sink. There isn't enough room in the cutlery draw since I got my Scanning Electron Microscope

The AAS is a perk of working at a university. That's not to say I have the slightest idea how to use it - but have a friend who does

Got home today and found lots of happy fish enjoying the cool water. Put in some food and they came up and ate it . They're a bit timid, but I hope they'll soon learn to associate me with food and come up to say hi... (i guess that might be expecting too much of a goldfish's mental ability.)

Hey... I've known teenage boys who've learnt to associate me with food and get out of bed and come and say hi...

Reckon you should underestimate your goldfish's mental ability....

Okay, this morning's update.

To my dismay, I went out this morning and found a dead fish in the sump. Other fish seemed happy enough (were all near the surface when I arrived, then darted away into the depths). I fished out the body and found it was quite discoloured (will post photos tonight). This discolouration is a sort of brown colour under the skin, and if I had to guess I'd say it was bruising. I have a theory...

Yesterday I noticed that one of the new fish had "overflowed" into the sump via the top of the CHIFT-PIST t-piece drain (I must put a fish-proof screen on that). My suspicion is that a second fish did the same, only this one had a rougher ride and got bashed around too much on the way down. Perhaps it even got stuck? The sump return line drains into a 90mm PVC standpipe (designed to deliver the oxygenated water to the bottom of the sump), so any fish that lands in there is subject to an almighty amount of agitation.

Anyway, I can attempt to disprove this theory when I get home tonight and count the fish in the sump and in the pond above.

Fish can swim through the darndest things. I've learned the hard way to always put nets or screens over the pipes.

Results are in from the Zinc test. I will post on a new topic as it may be of more general interest.

Fish absolutely LOVE playing in currents. Others take it a bit toward extreme sports, and ride the waterslide whenever they can!