Backyard Aquaponics
A place to discuss aquaponics

Ash the Algae on the tank wall is good stuff..

It will go to the brown type over time..
all of the algae I have on my tank is Brown and my system has been running for about 18mths now..

don't worry about algae on the tank walls it is a sign of a health system..

Juergen

Hang on, youve got 120 fish in that tank, and only one growbed? you should only have 25, 30 MAX with one growbed. your fish are probably dying because it is overstocked. also stop changing the water out, your only killing bacteria.
the reason your losing fish after rain is the drop in PH is killing off some bacteria, equaling less filtration capacity, but also stressing the fish.

IMO you need to do a few thing urgently
1- get rid of all but 25 of your fish (per GB) or add on more filtration. the situation will only get worse
2 - stop changing water out unless your nitrite / ammonia is off the charts

3- stop adding so much iron. AP mimics nature, so once cycles, the system should need minimal interference. my bet is massive water changes is changing ph, causing a nutrient lock out

4- if your going to keep all the fish, get another FT, other wise you will have DO problems as the water warms, and the fish become more active.

Thanks Juergen. The algae is much better since putting the shade over the top. Its a nice shade now and we won't be touching it

Freoboy - thanks for the pointers. Is the ratio 25-30 full size fish per grow bed? The perch are tiny and the goldfish are up to seven cm's - we had problems initially because we didn't have enough fish in there (about 40 goldies iirc). I understand that we'll need to look at harvesting the Perch earlier or giving most of the goldies away when the Perch start to grow, but we need the numbers now to get the nutrients into the system.
We've done two or three water changes in the last six or so months - this has been a last resort when we've lost half a dozen or so goldies. There have been a few times when we've lost between two and five a day for up to five days, and we lost about 30 in one week of December last year. Doing the water change and salting the water seems to stop the massive culling for a good while.

Ash,
yes that is 25 fully grown fish, but still you have way too many fish in that system. you should not need to do any water changes, period.

i am afraid its not a case of eventually getting rid of your fish. you have to many, and you will wake up to 120 dead fish one day. i can promise you that.

also, your system will 'run' with as little as 5-10 fish no worries, so you don't need all these fish to get nutrients.

doing so many water changes is only going to stress your fish out more. if the system was properly stocked, you wouldn't have any deaths.

i am sorry for being so blunt, but i dont want to see you lose all these fish over simple mistakes that could've been easily avoided

If you're feeding your goldies with the Silver Perch feed.. it's way too high in protein content for them... and ultimately, from my experience... they bloat and die... suddenly, after seemingly growing well...

+1

+1

Ash, now let's take a step back and think about it.

As FB said, there is no need to do water changes in aquaponics. Aquaponics is about maintaining a balance... If you need to carry out water changes every so often in order to stop your fishes from dying then something is out of balance... And now consider this, what is it that you are doing by doing water changes?? Reducing the amount of ammonia, nitrite and nitrate concentration. And how does ammonia, nitrite and nitrate get produced?? By stocking your system with fishes and feeding the fishes... So if your system is out of balance because of the excess ammonia, nitrite and nitrate produced, then have you stop to think that you probably have too many fishes or feeding the fishes too often??

It is a simple cause and effect scenario, because you will not get excess ammonia, nitrite and nitrate in your system that requires you to do water changes to reduce the death rate, if you have stock your system appropriately...

If you are not getting good plant growth, then the system might be short of other nutrients rather than nitrogen (or nitrates)... what is your water test results??

FB - "also, your system will 'run' with as little as 5-10 fish no worries, so you don't need all these fish to get nutrients." We ran the system with 20 or 40(?) goldies, and then 80 and it was crap for a very long time. It picked up a little when we started feeding the goldies the bigger (Byap) pellets, and now with the additional 40 Perch it is really starting to take off...over a year since we started Maybe the issue was using goldies instead of big fish, I don't know, but we are very reluctant to drop the numbers down given the fact that lower numbers stagnated the system for so long.

Rupert & Charlie - we are feeding them the same feed (crushed Byap pellets). We talked about what you wrote and it sounds like that is what's been happening. Other than getting rid of the goldies (which will happen, more a matter of when), I don't know how we can separate the feed when they're all in the same tank together.

Ivan - TY . The water test results have been very good and steady for a very long time. I'll check this again with the +1 and post up again. However, this is why we were changing the water - the levels were good yet we were still getting a dead goldie or two every week or so,then a spate of deaths in a very short time, water change, and then we're good again for awhile until the cycle starts over again. We've lost two goldies this week...good thing I didn't name any more of them huh?

We haven't lost a single Perch which makes me inclined to agree with Rupert and Charlie. The only other thing I can think of is the goldies attacking each other but there is no evidence of this, or a virus but I imagine this would affect the Perch also, and again no evidence of this.

And we finally have some good growth happening when the system struggled for so long. Granted, its not the growth that some have had on here but its brilliant compared to our early days. This also makes me reluctant to remove more fish, but this won't be a problem at the rate we're going...

Hmm what were you feeding the Goldie's when the growth was crap? BYAP still? My system took a good 6-8 months to start seeing really good growth

The usual goldfish feed (red and green 2mm(?) balls, not flakes). The combination of more goldies then using Byap pellets and then adding the Perch brought it up quite a bit, but other than some bok choy (forgot about that one!) and lettuce we've had zip from late August last year until one or two months ago. While we've still harvested very little, the growth is promising.

Thank god I've had my soil patches in the meantime! Sacrilege I know

Almost Garuntee that the shit feed, not lack of fish, was resulting in poor growth, byap feed contains alot of trace minerals and elements to get the fish pooing and plants growing

I feed my goldfishes the same feed as I feed my silvers, trout and barra. Skretting Nova 3mm. None of my goldfishes died. Although I did lose two kois and I am actually suspecting that the bigger silver perch in the tank might have attacked them as they were much smaller than goldfishes... Unfortunately I don't have proof, but two eaten up bodies of kois.

So what size silver perch did you buy and what is the size of the goldfishes compared to the silvers?

Yeah that coloured ball feed isn't much good...

The Perch were maybe 5cm when we got them. Fingerlings. And the largest goldies have grown to about 10cm, some are still quite small though. As we've had the goldies sinking and floating since the beginning, I don't think its a fight of the fishes. Checked with +1 and we have been feeding the goldies the Byap pellets for ages, possibly up to 12 months (I'm not so sure about this number, but definately 6+months ) . I checked how much we have been feeding - looks to be between 5 and 10 grams a day.

He has also confirmed that our levels have been very good. They were rocky for the first few months (as to be expected), and then once again just before we bought the Perch in May (iirc). We did a water change and salted the tank and were good for a little while.

But there is something a miss which is quite obvious with our tomatoes - we planted all but one of our seedling punnet in the grow bed about two months ago, and the remaining seedling in the ground. The growbed tommies are about half the size of the one in the ground and have what looks to be black spot(?),while the ground tommie has been nibbled by those dirty catapillars it is looking very healthy.

Has the tomatos in the AP ever been watered with seasol water... Especially on the leaves??