Aquaponics Home System – Part 19: Mold and Tannin

I don’t want to turn this blog into one about aquariums, but now that there’s an aquarium connected to the plant tank it’s part of the whole aquaponics system. Now that we have decided to use a normal hobby aquarium as fish tank we might as well spend some time making it look nice as a normal aquarium. If you’re not romantic at all you could just drop your aquaponics fish into a big black plastic basin – I don’t think the fish would mind.

We wanted to add some roots to the aquarium to try to recreate a real and natural looking environment, so we threw in a few pieces of wood that we found in the forest:

The problem is that the wood keeps floating since it’s not saturated with water:

The root to the right seems to be able to stay submerged. The other two are probably branches or stems.

The wood was left in the water in the aquarium for two weeks to allow it to absorb water to make it heavier so that it would sink to the bottom. What happened instead was this:

Nasty mold and what is probably tannin leaking into the water, changing the color of the water to light yellow:

Pretty nasty setup and delay before we’ll be able to add fish to the system.

The floating pieces of wood have been thrown out and the water has been changed. New roots from the pet store will be added together with stones to create the right look.

And now I’ll go open the door for the postman – he’s here with the water test equipment and nitrobacter 😀

4 comments on “Aquaponics Home System – Part 19: Mold and Tannin

  1. -

    I have been looking at the aquaponics set ups on youtube and there was a piece on our local news. I know when I had a 50 gallon aquarium going with 6 oscars I had to clean it every two weeks and change out half the water. When I saw the systems I viewed I was wondering if the under water filter system could just be circulated to the plants and returned to the fish filtered of coarse. My problem for a system like this i have to set up indoors as we live where we have six month winters. For now I will stick to my aeroponics system I made. Everything is working well and like you I want the most inexpesive food possible as the prices keep going up and I am eating less tomatoes these days because of it.
    Have a wonderful day.

  2. -

    @Scott: Aeroponics – interesting! 😀
    I’m just about to add fish to my system and hopefully the system will work. I have a bottle of bacteria ready to start off the ammonia oxidation. There’s a large surface available to the bacteria to grow on because the bottom of the aquarium is filled with rocks. I’m excited to find out exactly how much food this system is able to produce over time. And also, now that it’s indoors, if it will smell bad 😉

  3. -

    Hi Tom,
    What kind of fish? Keeping the fish alive can be a challenge in itself. Why is it you have to create a bacteria? Is it fish safe and friendly?
    When I raised Oscars I wanted to always keep bacteria and fungus from the fish. Those darn fish would eat almost anything. The fish emulsion from the tank every two weeks from cleaning was very powerful fertilizer, some of the best.
    My tomato plants are six weeks old right now and looking very healthy and I just harvested some fresh lettuce today for the first time. The pepper plants are growing well also and are three weeks old from seed.
    If and when you ever do smell something funky or see brown stuff a good cleaning is needed and from experience once it starts it is hard to get rid of and control but is manageable through regular cleanings.
    Now that is from raising fish and I keep the same practice on my aeroponic system.

  4. -

    @Scott: We now have 5 Bleeding Heart tetras (Hyphessobrycon erythrostigma) in the aquarium, plus 3 Pepper Cory’s (Corydoras paleatus), as an easy start to make sure that the water quality is okay before we add a lot of larger, and more expensive fish. They seem to be thriving so far.
    I’ve added nitrosomonas and nitrobacter bacteria to kick-start the ammonia to nitrate process – as far as I know it can take up to a couple of months for them to show up on their own, and I want to get the system in gear as quickly as possible to see some results. Those bacteria are supposed to be natural components in a natural, wild system.
    So far there’s no smell from the system but I’ve just added 7 litres (2 gallons) due to evaporation loss.
    Today I’ll go and pick up more fish to add to the system: Blue Acara (Aequidens pulcher), Firemouth cichlids (Thorichthys meeki) and Keyhole cichlids (Cleithracara maronii).

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