Backyard Aquaponics
A place to discuss aquaponics

You will find we do aim to please, just one big happy family here.
And welcome aboard Chris now post some pictures of your system, Please.

Did the bloom start shortly after this Chris?

Let us know when you post your pH tests.

Hi,

This mornings Ph reading was 6.2 by midday 5.9 but as I say I only have test paper so can not at this stage give reading on other elements. The temp in the dome ranges at the present from 20 - 38 C.

I have added an airator but it's only small. I haven't made any further change to the water today as it was only 9 days ago that I made a 100% water change. At that time the water was green and as was expected there was algae on the sides of the tank but no build up of feed etc on the bottom. After the change the water turned green within 24hrs.

The system is filled from rain water tanks.

The original feed used was Aqua Starter, it contained 50% protein. The Aqua grower I'm using now is 38% protein, 10% crude fat and 2% crude fibre. The pellets are considerably larger.

The dead fish have red area's under their scales around the pectoral fins and tail, as if blood is coagulating under the surface?

No change today, still have floaters, so I am still in need of guidance.

To VEGGIE BOY, sorry it took me so long to respond to messages but I am not connected to Broadband, so it takes an age to reconnect and get on line, the process is further delayed by the lack of experience and skill of it's operator.

Chris

Hi Chris, are you able to post any pictures of the system and the dead fish?

Sorry about the impatience of some of us, we are so used to people being on here 27 hours a day and answering questions in seconds. Some of us forget about dial-up

and jobs

back to work Mon!

Mate sounds like the low PH is putting your bio out of wack. Also the 100% water change would also further stress your fish and bio. It's no surprise that the algae came back so quick your rain water is probably full of nitrates. Put a cover over your tanks to stop that photosynthesis and raise your ph to around 7.4 this will keep your bio happy, get some test kits for ammonia, nitrite and nitrate. These test kits are essential in AP it will help you identify your problem.

Is there a lot of mucus on the fish? If there is the fish might have acidosis which is caused by a ph of below 6.

Now we need ammonia and nitrite readings. Looks like your bacteria have probably stopped processing the nutes due to the low pH. You need to gradually raise the pH - but want to make sure first that there is not much ammonia in the system (ammonia more toxic at higher pH).

Plan would be to do water changes to remove/reduce ammonia and then start gradually increasing pH by addition of a calcium carbonate source. Once pH is up a bit higher, the bacteria should start reproducing and working again.

Have a look at the Magazine regarding the toxicity of ammonia at different pH levels and the information we have provided on pH in general. Look in the Healthy Fish are Happy Fish article.

Let us know those ammonia and nitrite readings.

Did a bit more research for ya mate, it looks like it might be ammonia poisoning which would support the theory of the bio filter being off line.

I've got a sneeking suspicion that the nitrites might be off the scale as well.....

Can you measure your water temp as well Chris.... this is the determining factor as far as the ammonia/pH table goes....

chris, you best investment will be a master test kit. not that expensive and consists of high and low ph, ammonia, nitrite and nitrate.

with all those readings we should be able to give you a definative answer. if not then we'll just prescribe salt

....and cut back/stop feeding the fish for a few days

Reckon ya spot on Fil. Massive drop in pH has knocked out the bio. This means there is nothing bacteria wise to convert ur ammo thru to nitrite/nitrate, when u feed. What sort of pump drain cycle have u been running? You will find things won't improve much until u have a pH consistent around 7 and ur bio has re-established. Increase ur pumping cycle as much as u can, stop feeding and be patient. Check the pH of ur water b4 you add it to ur system. Look at possible causes of poor water quality.
The red spots are nitrite toxicity. Brought on by nitrate reconverting to nitrite due to inadequate pumping (or pumping thru an anaerobic bio in my case.) Is a large part of ur bio permanently under water?

My experience when playing around with biofilters that stopped working due to low pH was that as soon as the pH was upped - the bacteria was processing again really quickly. A lot of the bacteria may still be there, just not working at present.

Need those other tests - would hate to see pH whacked up and then fish killed due to high level of unionised ammonia.

Thanks for the feed back. Will go to the big smoke tomorrow and get a test kit and let you know what results are like.

Thought the Bio wasn't working but didn't know what was causing it! The pump is pumping the maximum volume of water possible each cycle, which means that over a thousand litres goes through the beds. On average about 5cm of the 30cm deep beds are permanently under water.

I have posted a photo of the system, which I hope someone can find, but as for dead fish yet to come.