Aquaponics Adventure Mark II part IV

Aquaponics - 1 Comment » - Posted on May, 17 at 4:30 pm

This is a continuation of my photo blog of my aquaponics project. See part III to get up to speed on the story so far.

In my last post I said we’d keep an eye on this guy:

Well this is what he looks like now:

He’s healed, but dead. My girlfriend unplugged the bubbler in the hospital tank to charge the batteries for her electric bike. Unfortunately, I didn’t notice and I think this guy died of a lack of oxygen. I was pleased to see that the wound had healed though, but then I saw this fish:

Either it’s a transvestite, or it’s got bleeding lips. I queried the knowledge banks of the BYAP forums and the people there seem to think that it’s just fish fights. Nothing to be worried about.

Anyway, I decided that I should revamp the hospital tank to be like a little mini-system. Why do you need a hospital tank? Well, when you first get a new batch of fish, you want to isolate them somewhere and make sure they arn’t introducing disease into your established tank. So you put them in the hospital tank for a few weeks and monitor them. Also, if fish get sick, show signs of fungus, bacteria or even fish attack like this one, you can pop them in the hospital tank and hopefully give them a speedy recovery. There are few things that you must do to the hospital tank for it to be healing for the fish.

  1. The salinity levels must be higher than the main tank. The difference in salinity level helps kill off parasitic single celled organisms, as explained here.
  2. The water hardness should be comfortable for the fish.
  3. For diseases like ICH, the water needs to be heated to a temperature which speeds up the breeding cycle. Salt water won’t kill it while it’s in the fish, but if you speed up the breeding cycle, as soon as it hits the open water it will die. Since it needs to go to open water to develop, it will eventually die off in the body and won’t have reproduced, therefore your fish is healed. This is explained much better here.
  4. Lots of O2. According to the BYAPers “Salt will slightly decrease the amount of O2 that water can hold.” And there isn’t a fish that complains about too much O2!
  5. Water conditions similar to the main system. One thing that seems to really knock fish around is changing water conditions. So if I drop my fish that are used to water of pH 7.4 into a pool of water with a pH of 6.0, they’re going to really struggle. So it’s quite important to get the systems in sync.

So here is my hospital tank:

 

The pump is pumping water up onto the roof of my shed, the idea being that it will collect a bit of heat from the sun to warm up the water. At the moment, the tank sits in full shade, all day, and is about 2 degrees colder than the main system. So the water gets pumped up onto the roof as a kind of dodgy solar heater:

 

And then returns back through a mini bio-filter:

 

It’s all covered up to stop it collecting leaves, and I’ve got the air stones for the bubbler in as well.

 

The main system seems to be doing OK. I got a reflective surface setup at the back of the bathtubs in the hope that it’ll help the veg, I am yet to angle it so it reflects the light down, but it should be reflecting some light as it is:

And the plants still seem to be growing slowly:

 

 

 

Aquaponics Adventure Mark II part III

Aquaponics - 1 Comment » - Posted on May, 13 at 1:23 pm

This is a continuation of the aquaponics adventure from part II.

It’s been a couple of weeks. We’ve had the system going, and we’re waiting for the bacteria to establish themselves. We know the system is going (”cycled”) when we see this:

That is, Ammonia (right) Zero, Nitrite (middle) Zero, Nitrate (left) > 0. This means the fish excretion Ammonia is being converted to Nitrate! It’s cycled.

But it’s not all plain sailing from here. Fish health is a major consideration, and here I was thinking my system was chugging along smoothly and I post in a thread on the BYAP Forums “I forgot to feed them this morn. Looks like they took it out on this little guy. I’ve entitled this picture “Look ma, no tail!” Watching him swim is funny.“:

And someone wrote back with “It is bacteria not fish attack (fin rot) if i see well on the pic.
Treat with salt quick before it goes further.”

This guy ended up dying. I have treated my system with salts and have even built a hospital tank. But I’ve lost about 5 fish out of 74…

Here is another one that died. Notice the blood on the fins - once again, some sort of fungal/bacterial infection:

With these problems, it’s not good enough to treat the fish and hope it goes away, you have to find out the cause. I think water quality, low water hardness, and my fish feed being a couple of months out of date contributed to the problem. Apparently as fish food ages it loses it’s vitamin content. I’m pretty sure I’ve got the water conditions right, and I’ve bought more food, so hopefully the cause is no longer a cause.

However, there is this guy. He is currently in the hospital tank - I’m not sure whats happened to him, it doesn’t look the same as the fungal problems, I think it might actually just be because he’s the little guy and has been attacked by the other fish. I’ll report on his progress next post:

Anyway, the other end of it is the plants. So here is a quick update on their progress.

Here’s some spring onions and lettuce I planted on 5/4/08

Here they are a month later on 04/05/08:

This is actually pretty slow growing for an aquaponics system. And I have a few suspicions as to why - firstly, notice that in both shots the plants are in shade. I don’t think the vegies are getting enough sun, they need at least 6 hours a day and I suspect they’re not getting this. Secondly, fish provide Nitrate, but they can’t provide Iron, Manganese, Potassium, Calcium and all the other trace minerals needed by plants to grow. So I need to add something else - in this case I’ve added a splash of Seasol, and a tablespoon of Iron Chelate. I’m going to put a reflective surface up the back there to reflect a little more light onto the plants. That should fix the light problems, and I reckon the nutrient problems are an easy fix, so hopefully in the next month we’ll see much better growth.

Here’s a final pic of my fish getting a tasty treat of worms from my worm farm. Notice how clear the water is compared with part II - the socks have done their job: