Backyard Aquaponics
A place to discuss aquaponics

I have been developing my system for the past two years. Gone through many issues (dead fish; failed timers etc) but now my system is running happily with healthy fish and no problems with timers, pipes or pumps. There are two separate systems - one with gold fish (20) and one with silver perch (24). They are both CHIFT PIST.

Ph 6.7; Ammonia 025; Nitrate 10; Nitrite 0 - for both systems.

My issue is, that I am very disappointed with the growth rate of the vegetables so I am seeking to find points of difference with my systems and other systems that are successfully growing.

Sizes:

Gold fish - 90 litre tank; fish 4 to 10 cm in length. Two grow beds (40 l each). In operation for two years.
Slver perch - 450 litre tank; fish 10 to 12 cm in length. Four grow beds (70 l each). In operation for about 6 months.
Filling in grow beds - 12 mm drainage gravel. (Should I change to clay pebbles?)
CHIFT PIST - the water is pumped from the sump to the grow beds then back to fish and then to sump. (This seems to be a difference to other systems - but is it relevant?)
Timing - 10 mins on every hour 24hours a day (Am I watering too much?)

Any thoughts appreciated.

I don't see any problem with what you have mentioned there. Though probably the most important bit is the feed, what feed are you using and how much are you feeding them each day. Also what plants are you growing? Are they in season?

bruce: My system is not nearly as old as yours but I was experiencing similar issues: healthy fish, good levels (except my PH was high), but really poor growth. I tracked my PH to limestone being in my gravel medium and am staged to replace it with Hyrdroton. I think the high PH was locking out nutrients. Your PH seems to be ok, so limestone is not likely your issue.

What is your lighting situation, is your system outside? Air temp? Also, what veggies are you growing?

It doesn't sound like you are watering too much. How long does it take for the GB's to drain? If they take forever to get rid of the water your roots may be rotting or not getting enough oxygen between flooding cycles.

Thank you both for your rapid responses.
Type of feed: Gold fish - fish flakes (from Woolworths); Silver perch - pellets from pet shop. Both about 35% protein. Feed once daily - the goldfish will eat constantly - I also give the goldfish a handful of duckweed every now and then). Any suggestions here?
Lighting - The systems are in a screen covered frame - sunlight about 8 hours each day. Temperature relates to outside temp. Don't know exact temp in shed. Although at height of summer it does get hot because of clear roofing. (It was too hot for tomatoes and they wouldn't fruit as the flowers kept falling due to heat).
GB drain time - one GB in the goldfish system has a bell drain and the other GB has a hole in the overflow pipe to slowly drain once the pump stops. Takes about 10 to 15 mins to drain.
Current plants - Mizuma; Pak Choy; Tatsoi; Brocoli; Lettuce; Silver beet; Tomato ; Capsicum; Mint. The Mint is in one BG on its own and is going well.

Maybe I am expecting too much from my system - but I can honestly say that I haven't had a feed out of it in two years - the first tomato ( of a max of 5) would have been worth about $500!

Your system is probably lacking some of the essential nutrients... apparently these are normally present in aquaculture feeds... you could alternatively supplement the system with some seasol and chelated iron...

Consider changing your food to some commercial aquaculture food (ie. Ridleys, Skretting, Grobest, etc) as they are formulated for growth hence produces more waste...

I second the opinion on the feed being the issue. Even with my pH high enough to cause many plants to struggle a bit, I still get good growth. I have to supplement Iron because of my high pH.

Many people swear by using a good amount of seasol or Maxicrop for the first year or so to provide lots of trace elements and potassium. I dose with maxicrop original about every month or so. A few cap fulls each week in a system the size of yours would probably do some good.

I swear by using a hand full of worms and castings in each grow bed on start up.

But for ease of dosing and long term success and health of your silvers, switch to a complete aquaculture feed. Saddly most pet store feeds/aquarium feeds are designed to keep the fish alive while imparting the least possible nutrient load to the water. This might be great for people with aquarium who don't want to change out water as much but it doesn't really help us who wish to grow veggies on the nutrient rich water that we are not changing out.

How much oxygen are you pumping into your system?
something i think that turned my system around was getting more dissolved oxygen into the system.

I was at first relying on the returning water from the growbed.
My system was a 160Lt barrel FT with another 160lt barrel split in half to create 2 GBs on top of the FT. At first i relied on the returning water to create enuff Dissolved Oxygen but i dont think it was enuff.

I pulled out some of the slow growing plants and noticed their roots were brown and not many white roots. So i suspected root rot from just drowning it in water.

SO, I tee-d off the main pipe up to the GB and put in reticulation pieces or 4mm retic joiners into the Tee-d off pipe. They would shoot water back into the tank at a decent intensity. I put around 7 or so of these to do this.
This created a fair amount of bubbles every time the pump turned on.

U mite be able to see the first retic insert and maybe even the 2nd but u get the point.

My system is going extremely well now and i do put it down to more dissolved oxygen and also some doses of powerfeed and seasol

Thank you to everyone for your interest and your suggestions.
Oxygen: For my goldfish it is provided by the returning water and for the Silver Perch I have two air pumps.
Supplements - I have tried Seasol but it is a bit of a guess as to how much - currently I am trying to apply Seasol by spraying on the plants (foliar application as the Seasol people say).
Worms - I have tried a few worms - but I will put some more in .
Fish food - I will try some better quality fish food. I think this may have some effect.
Again, thanks for all the suggestions. I will let you know what happens.

100 percent low feed quality. Pet shop fish food is designed to have a little nutrition as possible, this is to reduce the amount of pollution in an aquarium situation.

Being a mature system you could quite easily feed the fish as much high quality food as they will take, you will see very good results.

Bruce, I would do as outback said. Get some better quality feed.

On top of that I would also add some micronutrients. Chelated iron being the most important. Maxicrop is good but I think in your area there's seasol. I found that micronutrients, or a lack of, was my problem.

Yeah we have used goldfish flakes here before in some systems and you don't really get much in the way of plant growth...

Can anyone suggest higher quality gold fish feed here in the States?

I use Aquamax dense culture feed.
http://www.purinamills.com/OurProducts.aspx?product=fish
It is a purina product. I call a local feed store that is a purina dealer (but not tractor supply as they won't special order anything in the way of feed even through they are a purina dealer now.)
Anyway, ask them if they can have a bag of Fish feed put on the next delivery for you, find out price and when you would have to put in the request to get it by the next delivery date and when that would be and so on. The dealer near us puts in their orders on Monday Mornings and the truck usually gets in on Thursday afternoons. Other stores might be on bi-weekly deliveries or other schedules.

Anyway, you can go onto the Purina web site and research the different feeds they have available and the different sizes, if it sinks/floats and the % or protein. I would stick with the Dense Culture stuff as it is meant to be a complete diet. Sorry I don't know what feed would be best for goldfish though.

Again, thanks to everyone for your input.
I have ordered some silver perch food (from the people who supplied the fingerlings).
Any suggestions regarding the goldfish food?

I'm having almost exactly the same issues but I've been using grobest for a few months with no improvement other than faster fish growth.
My timing is 15/45. The beds fill in about 10-11 minutes then take 40 min or so to drain...is that too long?

In addition to the water splashing into the beds, it splashed into the sumps and I have 1 airstone in the main fish tank...is that enough for the veggies?

Would my gravel being only 18-20cm deep be the problem?