Just not happening

[Charlie]

Hi all
We are looking for some advice. We have had a system trying to operate for some months now. Has 200 very small silver perch that are surviving but not very active. It is pretty cold here though in SW West Aust. Nothing seems to grow - silverbeet seeds geminated but only grew about 3cm high. Also have heaps of Algae in the fish tank. Can anyone offer some solutions. :(

[Murray]

Hi Charlie,
Have you got the tank under cover ?
Is there direct sunlight getting onto the surface of the water ?
How does the water test for Ammonia, Nitrates.
What is the water temp ?
How much food do you give them each day ?
What kind of food ?


Just a few questions to get started on.........

[Hamish]

My guess is the Algae will be robbing all the nutrients.

Murray is right - post your water test results. Nitrite, Nitrate, Ammonia and pH.

Get a cheap min/max water temperature recording sensor - I have them for sale for $20+$5 postage if you want one. Email me or PM me if you want one.

If you get your water temp and tests all right then your fish will be happy so they eat - and make waste - and once cycled so the bacteria is all well established the plants will grow with the nutrients.

I notive my water temp is about 21.5 in the morning and the Jade perch wont eat much if I feed them first thing. But once the water warms up to about 23 by mid morning they are right into their food.

[Jonathan Dyer]

I drunk Kirup Syrup and survived! :p

Hi there Charlie,

Aquaponics can be a bit fiddly, but knowing the local conditions I would say that your biggest concern is the water temp is far too cold for silver perch. I know my system every night currently gets down to around 8C and I’m further north than you are but I’m growing koi and goldfish able to still grow and perform at these temperatures as well as growing silverbeet in my growbeds but they do grow slow at this time of year.

I recommend that you heat the water up by some means and depending on the size of your tank the easiest way to do so is a few aquarium heaters (3x 300w for say 2000L tank) try to aim for about 25C if you can.

At the same time your algae bloom needs to be treated straight away or possible risk the loss of all your fish. I would do a 50% water change and go out and buy some pond algae killer (a very weak solution of simazine) brought at the local hardware will fix the problem completely but double the dosage recommended and keep a close eye on it, however, if your trying the ‘Organic’ way of food production a 99% water change would be needed and some barley straw in a shade cloth bag submerged in the water will also work. Additional oxygen supply to your fish tank is crucial as the algae will supply oxygen during the day but at night will rob oxygen causing stress on the fish which intern can die, an aquarium fish pump with an air stone will help no end, if its only a small pump 2-3 would be best.

Once you have these intact you system will stabilise very soon.

And Hamish even rainwater left in a bucket with no nitrates for a week or two will start to grow algae, it is not always the presents of nitrogen that makes algae grow, yes, the more nitrogen the faster it will explode that is true but not always the case. 200 small fingerlings don’t produce too much nitrogen.

Charlie had your microbes built up enough in your system before you stocked the fish as that can also be responsible for you bloom? If they haven’t been given a minimum of three weeks to build up numbers befour you added your fish what Hamish said would be correct as the algae would grow and out compete nutrients from your plants due to an imbalance.

How many liters is you fish tank?

[Jonathan Dyer]

I double checked an algae killer product by PETS I have used in the past and the active ingredient is Diuron which works well but I have also seen products with Simazine same effect. The product is fish safe and will not affect your silverbeet or other plants, if you have duckweed/azolla growing in the same water it may affect it I’m not sure, but works great and cheaper than loosing 200 fish.

[GaryD]

Hi,

I would think twice before I put any chemical in my tanks.

There are many remedies that won't kill fish but which are banned around fish intended for human consumption.....eg...Potassium Permanganate, Formalin, Malachite Green, etc.

Your situation is different Jonathon......you're not going to eat your Koi or Goldfish.

Gary

[Jonathan Dyer]

Gary,

Whether you like it or not you have eaten these chemical residues in your life, yet they would be almost undetectable.

By the time the algae has been controlled and numerous water changes the chemical in the fish tank in a years time will be undetectable. You could drink this stuff and you wont die, it may not be good but I don’t think you will loose 10 years of life because of it.

Algae killer will control the algae bloom which is detrimental to the system and the fish and in only a few weeks time the system will stabilise. Over the next year there will be no chemical residue left in the tank due to numerous water changes and dilution as well as chemical break down. But if you don’t believe me what is your recommendation?

[Hamish]

I like the idea of the barley straw - seems like a nice healthy way. Perhaps just blocking all sinlight to the tank for a couple of weeks at the same time as placing barly straw under the return to the tank (so all the water has to flow through it) might work? Or perhaps a canister filter like the one I have set up and run the UV light for a week or two?

[notable]

hi Charlie
Lets get back to basics. A few months ago I had an algae problem, so I:
Covered the pond to stop direct light
Installed an air pump
Cut out feeding the fish for a few days
1 week later no algae
My silvers are hibernating at the moment, water temp is 12 at night to 15 by day, so I have put some lengths of 90mm PVC drain pie in the tank so they have a protected place. Minimised feeding to every second day. Adding some trout tomorrow as a short term, 6 month solution, that willl give me some minitrout fillets for summer, (see I have created a market for undersize fish),so the nutrient for the veg will continue. Adding a third grow bed this weekend.
keep at it
cheers
Rodney

[GaryD]

Hi Jonathon,


But if you don’t believe me what is your recommendation?

I have no crisis of belief around you.....but you are repeating advice that is provided by chemical companies and there is plenty of evidence to suggest that they can't be trusted.

The 'pea soup' phase of a start up invariably affects all outside aquaponics systems initially.

As for my recommendation......cover your fish tank, stop feeding the fish....and wait.

Gary

[Sunshine]

I went through a dificult time getting my water clean and had numerous algie issues that killed heaps of fish.

I now run a small pump continously into a filter that has bio balls on one side and filter media on the other. I bought about 10 metres of bulk filter material and folded it into my home made filter. Also have two air pumps going at all times

This works really well and my water almost shines it is so free of minute particles. The downside is every month or so it takes me half and hour to rinse the material and clean it.

Havent killed a fish in a long , long time.

[Hamish]

I am getting similar results from the canister filter - my water is so much clearer now. Even after adding 2 new clay ball grow beds. I thought the dust from the clay balls would mess up the water - but the canister filter cleared that up in a few days.

[Sunshine]

I am not convinced that the growbeds will clean your water. Sure the plants will extract what they want but to keep the hygene of your water up to speed I believe you need to filter. I 've had 300 dead fish to verify line of thinking.

The filter does not need to be expensive. It just need to work effectively. A $30 pump, a container and some media and your in business. Or you can go the UV lamp models. I do both.

You can rationlise the cost on what 300 dead fish are worth.

[Hamish]

My canister filter cost me $175 + $15 courier. It has an 11W UV sterilizer lamp you can switch on and off independent of the filter - and it is rated at 2800LPH which seems pretty good. Totally silent too which is great if you have neighbors close by like me :(

http://cgi.ebay.com.au/2800L-H-CANISTER-FILTER-WITH-11W-UV-STERILIZER-NEW_W0QQitemZ310055077759QQihZ021QQcategoryZ20754QQtcZphotoQQcmdZViewItemQQ_trksidZp1 742.m153.l1262

[Charlie]

Ammonia 0ppm, nitrates 0ppm, fish tank under clear roof, fish feed comercial fish flakes approx 1/2 teaspoon, temp 13 degrees.

Thanks

[Hamish]

Zero Nitrates means the plants are getting zero nutrients.

The fish are probably slow to eat and create waste because the water is cold - try adding a heater and get it up into the 20's if you can. I notice there is a fine line with my Jade Perch (21 and they dont feed much 23 and they eat like pigs) same goes for the gold fish I have in the same tank.

Keep the tank covered to exclude light and kill the algae - will also help keep the heat in and lower the power bill. Perhaps a piece of that floating pool cover that looks like black bubble wrap would be easiest? Leave a small gap around the edge to let gas exchange happen.

Once the algae is killed by excluding the light the nutrients will be available to the veges - rather than being taken up by the algae.

Once the water is warm the fish will eat and produce waste for the plants.

What are your Nitrite and pH readings?

[Jonathan Dyer]

Charlie, How long has your grow beds or bio-filter been in place? It may not have an established bacteria count strong enough to cope with the system sometimes it takes over two months at those temperatures. A hand full of urea will help kick both the bacteria and your silverbeet along nicely. But make sure you kill the algae by whatever means necessary, covering the tank to exclude light may take too long and by then you may have dead fish.


I am not convinced that the growbeds will clean your water. Sure the plants will extract what they want but to keep the hygene of your water up to speed I believe you need to filter. I 've had 300 dead fish to verify line of thinking....You can rationlise the cost on what 300 dead fish are worth.

I couldn’t agree any more, you have hit the nail on the head.

[Murray]

In for my two bobs worth.
I have a pressure canister type filter with UV light. I do not use the UV light much as it strips boron and magnesium from the system if you leave it on all the time.

I change the filter around from system to system when I need to clean up the water a bit in an individual system.
If I am getting a algae problem developing in a particular tank, I hook up the pressure filter, scrub the tank walls and floor with a stiff broom I have especially for the purpose.
Run the pressure filter with UV light on.
Re scrub the walls and floor of the tank every day for 3 or 4 days and the tank clears up as if by magic.

Once the tank is clear I continue to run the pressure filter for another week or so to polish the water. (with the UV light off)

When I clean out the pressure filter I put the muck back onto the top of the grow beds.

[Jonty]

Charlie,

Here's my two bobs worth on the algae problem. I started off a new tank early December 2007. By January my water was pea soup green. I maintained the oxygen in the water with two airstones. The fish continued to eat and grow. As the weather cooled around May the ammonia levels increased as the algae bloom started to die. The ammonia levels then quickly settled.

The growbeds did suffer initially as the algae feed of the nutriment but I kept adding Charlie Carp to maintain the vegies (nitrate was around 5). I probably kept the algae bloom going but I did not lose any fish. My pH is 6.0.

The only drawback was that I couldn't see the fish. Nitrate is now around 80 and the water is now clear.

I had numerous discussions on this forums with members suggesting replacing water and/or the algae killing fish and/or releasing toxins in the water. I ignored all the advice and did it my way. Sooner or later you system WILL balance out.

Regards
Jonty

[Charlie]

hey murry

My aquaponic tank is situated outside under a clear roof cover providing it with sunlight.
The fish get fed fish flakes about 5 grams per feed.
The water is a constant 13 degrees.
The Amonia is at Zero parts per million
same with the nitrate which is Zero parts per million.

Thanks Charlie

[Murray]

Hi Charlie,
Direct sunlight on the water will always give problems with algae. First step in controlling algae is to cut the direct sunlight. That has been my experience anyway.

[GaryD]

Hi,

In the interests of not confusing newcomers to aquaponics, I've put the following information together in an attempt to enable people to find out the relevant information about algae blooms without having to rifle through pages of (sometimes dissenting) posts.

Once I've given everyone enough time to contribute further, I'll create a clean thread for our Useful Information section.

At this point, here's what I'm proposing......

Sooner or later, an algal bloom will impact all aquaponics systems. Aquaponicists refer to this phenomenon as the ‘pea soup phase’ and it is the consequence of two things……light and nutrients.

It is most likely to occur soon after (or even during) start up and at the beginning of Spring. In both situations, the algal bloom occurs because the biological filter (or grow bed) is not adequately conditioned for the organic waste levels in the system.

In the case of the start up, you may have fish that are eating more food than the bio-filters can handle. At the start of Spring, the water becomes warmer and the fish begin to eat more…but the growth in the numbers of nitrifying bacteria will lag the increase in ammonia production……and algae will begin to colonise the system.

While their presence irritates us, the algae are performing a useful function. In the absence of sufficient bio-filtration, the algae begin to take up the ammonia in the water. This detoxifies the water and makes it safer (than it otherwise would have been) for the fish.

In the process of course, it turns the water green and denies visual access to the fish and, once the algae are established in the system, they compound the problem because they cover the bio-filter media and further retard the growth of the nitrifying bacteria.

The other more serious downsides of an algal bloom in your tank have to do with oxygen levels and pH. Algae take up oxygen during the night and give it off during the day. In extreme situation, fluctuating oxygen levels will stress (and may even kill) fish. Of equal concern, is the fact that the presence of algae will cause the pH to rise. This results in a higher ratio of un-ionized ammonia to ionized ammonia so any ammonia in your system is going to become more toxic as the pH of the water rises.

I said earlier that algae are the consequence of two things……light and nutrients….. and therein lies the secret to controlling algae.

Resolving the light problem is easy……you simply cover the tank. Alternatively, you can house your tanks inside a shed.

If you use grow beds, ensure that the water only rises to within 25mm - 50mm of the surface.

Denying the algae access to nutrients is largely a question of good management in that:
You should be feeding enough to achieve useful growth rates without wasting feed…..which eventually becomes ammonia.
If you have adequate mechanical and biological filtration, you will have less of a problem. Where you do find that algae have invaded your system, you will get rid of them much faster if you do the following:
Ensure that you have adequate bio-filtration for your system.
Use mechanical filters to remove all solids from your system…..they clog the bio-filters and increase the ammonia loading.
Increase aeration……air pumps are cheap insurance for any AP system.
Cover your tank.....or house it in a shed.

Reduce feeding.
Use an inexpensive UV system to kill algae cells.
Use water plants to extract nutrients.You may hear people recommend water changes as a means of ridding your system of algae. This is not only a waste of water but its effect is temporary – the algae will return within days.

To summarise:
Algae will make their way into your system eventually (algae spores are carried on the wind).
Don’t over feed your fish.
Cover your tank to exclude direct sunlight.

Ensure that you have effective mechanical and biological filters.
Increase system aeration.
Ensure that the water level in your grow beds only rises to within 25mm to 50mm of the surface.
GaryD

[Hamish]

To summarise:

§Algae will make their way into your system eventually (algae spores are carried on the wind).
§Don’t over feed your fish.
§The best control is to have effective mechanical and biological filters.
§Increase system aeration.


Could I suggest you add something like this to the summary:

Exclude light to the tank and make sure water is only flooding to a couple of inches below the surface of the grow bed media (not over it).

[GaryD]

Hamish,


Could I suggest you add something like this to the summary:

Exclude light to the tank and make sure water is only flooding to a couple of inches below the surface of the grow bed media (not over it).
Done!

[Jonathan Dyer]

Use an inexpensive UV system to kill algae cells.

I have never seen an inexpensive UV filter before.



You may hear people recommend water changes as a means of ridding your system of algae. This is not only a waste of water but its effect is temporary – the algae will return within days.

I’m sorry Garry commercial aquaculture frequently recommends water changes to assist riding a system of unwanted algae blooms. “The solution to pollution is dilution” One of the most important fundamental rules of good fish management; you are diluting the algae bloom so it is less of a hindrance to control making filters more effective and reduces cleaning time (sometimes altogether) in order to remove its presents totally by appropriate means. Additionally, you are removing excessive ammonia levels which intern lowers the risk of another bloom starting. Don’t forget when algae dies and breaks down it produces toxins that need to be dealt with and removed or risk depleted oxygen levels, high ammonia spikes, high carbon dioxide levels and other toxic byproducts which intern causes excessive stress on your fish shortly leading to death, good bacteria levels in your bio-filter are essential at this stage.

This problem is of lower risk for smaller fish but as the fish come near to maximum stocking rates of what the system can handle, that’s when a slight imbalance can cause chaos. Keep than in mind.

Look most people will work it out for themselves but as Sunshine said “You can rationlise the cost on what 300 dead fish are worth”.