Backyard Aquaponics
A place to discuss aquaponics

Hello all,

I have a 1000 litre tank for my 7 rainbow trout with a grow bed on top of it and a sump tank with pump in it that receives its flow from the fish tank. The pump pumps water to the grow bed and runs a venturi setup in the tank.

But I have been unable to get to the tank because of the grow bed on top so I am looking for a new design. (Any suggestions would be greatly appreciated)

However my biggest problem at the moment is that the tank now has a green tinge to the walls and water (Yes, I know I should have painted it, or covered it but I was slack) I now have some mini orb cladding to go around it when I get the grow bed off it. My fish seem to be still feeding ok, not that I can see them at the bottom, but I certainly see them when I throw food in. I have just got 5 x 50mm uniseals to increase the pipework and get some better flow happening (presently all fittings are 40 mm. But as luck would have it, it is pouring rain for the next day or two.

Anyway after that long winded feedback, my question is
Will the algae harm the fish? Will they survive for a few more days? I know it is not ideal but I cant do much in the short term, short of getting another tank and putting them in there till I sort things out??

Regards
Rod

The algae can be a problem, it depends on how much there is.
the risk is related to oxygen levels at night when algae respires, lowering the oxygen available to the fish. If the algae dies, which will happen when you block its light, it will decompose and use up more oxygen. This might not cause much of an issue to some kinds of fish, but trout like clear, well oxygenated water.

How quickly has the algae developed? What is your nitrate reading and temp?
If the water is relatively warm, and the nitrates are high, with the long nights you must have over there at this time of year it could be a critical situation. If this is the case i would do water changes and plenty of aeration, especially late night and early morning. As well as cladding the tank of course.

Thanks Danny,
The algae has been building for say 4 weeks and has just got bad in the last week. I have plenty of oxygenation I am sure. the water is bloody cold (winter here, and we are averaging 12 in day and 9 or so at night. I havnt tested water for a while but will do so today if the rain holds off for a bit
I will come back with readings
Cheers

just tested water and PH is up above 7.6 (always has been) ammonia is at 0.25ppm and nitrate is 5 ppm

Sounds good, you're probably fine to just clad it up and let the algae die back.It's goo that there's rain, so you can exchange the water if needs be, just in case it gets a lot greener.

I have rarely run into issues with surface algae harming the system or fish, as the fish in the system usually graze on the algae and keep its populations in check. I am not sure if trout do this, but if they do not, it may be worth introducing other organisms that can graze on the algae that will not be attacked or preyed upon by the trout. I have used snails for this purpose (although fish will eat them) and have also considered introducing Plecostomus in the past.

Suspended algae should never be present in a system in noticeable quantities, but it is easy to deal with using a UV clarifier/sterilizer. An appropriately sized one will remove all suspended algae within a few days.

Also I am worried about your pH and ammonia levels, I would reduce your feeding so that the ammonia clears! From my understanding, trout are very sensitive to impaired water quality, and the toxicity of ammonia increases proportionally to pH.

Asking for advice again fellow Aquaponicists

So I have placed my trout into the new tank that was 3/4 full and clear as. When I placed the fish in, I set the old tank up to be sump tank. Its water was green and unclear. Then stupidly I placed about say 100 litres of that water ( rather than waste it) into the new tank and now it is green and unclear. Has been for 24 hours.


Can I buy a product to get rid of the algae that is safe for the fish? Or just keep the tank in darkness and wait for the algae to die. How long would that take. The fish BTW seem fine

I'd keep the tank in the dark. The algae will die out, usually within a week or two but the tank should remain pretty dark after this to keep the algae from re-establishing.

Controlling the nutrient levels by getting your system in balance is also a good thing. You can increase the number of plants to use up the nutrients or you can purge some of the nutrients by replacing 10 or 20 percent of the system water on a regular basis.

Thanks Scotty435,
Have covered tank with a tarp, and placed shade cloth over all outlets to capture solids and aerating 24/7
tank is clearer already today, so in another 24 to 48 hours all should be good. (I hope)
Also feeding less, now only once each day. will start to increase that tomorrow I think

Nothing seems to be working so I bit the bullett and replaced 70% of the water with water straight fro the tap. 24 hours ago now and fish are fine,feeding ok. I did add some worm castings to the growbed and water conditioner to tank. Now I am figuring that if the fish survive now, I may have killed of some bacteria in the growbed which will effect levels and give ammonia or nitrite spikes. I'm just so Pissed off with it all. It is the middle of winter here and I just cant stand being out there in the cold wintry conditions

I have also bought new 16000 LPH pump and had to plumb that all up and got covered in mud and water.

If it all goes south I will re design setup and restock when it gets better weather.I know where my design is faulty but as I said, I just can't stand being out there in the cold.

My the trout will taste good if I get to that stage. I questioned myself as to whether I had lost the passion for this hobby. But no I love it. Just hate Melbourne's winter (having come from Queensland)

Doesn't sound too bad. Enough of the bacteria may be OK especially if there was a lot of organic matter in the system. It's good that you're at the cooler time of your year since that will help keep most of the ammonia in the less toxic form (see table here - http://ibcofaquaponics.com/information/tables-and-charts/).

Salt the system water to 1 ppt to mitigate the toxicity of nitrites (although this will affect strawberry plants).

Cheers

The problem just keeps persisting. I placed a large pot plant plastic holder with holes at the bottom and suspended it of the sump frame. In it I placed polyester and shade cloth and the SLO runs into it, well it turns green and gets rid of a lot of algae, but what ever I do the tank has just not cleared. Whats the point of having fish if I cant see them, right? So I bit the bullet and bought a chemical product to rid the IBC of Algae. Now it cost $26 for 275 ml. I treated the tank this morning with 25 Ml (the recommended dosage for 1000 ltrs)
Will it kill the fish, will it kill the bacteria, will it kill the plants? According to the pet store where I bought it the answer to all of the above is NO
what do people reckon?

Any experiences in doing this? I know that chemicals should be avoided, but I was at my wits end, and the fish wont be ready to eat till November so any impurities will be well and truly gone by then

TIA

Sorry to hear you weren't able to rid the system of algae yet. I haven't tried doing what you did but hopefully the product you purchased isn't high in copper as some are (odds are if it's safe for the fish it probably will be for you as well but it's definitely use at your own risk). Some algicides apparently use barley straw extract and I forgot to mention that some people have used barley straw to clear out algae in their AP system.

Well I did loose one fish, but that appears to be from a jumper as I found him on ground this morning. The algae has cleared considerably and the other fish seem OK. BUT they are NOT feeding??? Iv'e just done my first water testing in over a month and the PH is extremely high at 8.2 ppm (what can I do to lower this?)
All other levels seem OK Nitrate maybe at 5 ppm but probably less
So hopefully I can get back to a level playing ground soon. I will try to feed fish tonight and see what happens.
But a lesson learned, once the trout get to 4 to 5 hundred gram in size cover tank so they cant jump out