What do I keep in my cupboard? (part 1)

I have just completed murdering an Aiptasia which was living amongst my Zoas in my marine aquarium and it got me thinking about all those things which live in the cupboard under the tank. Between my two cupboards, the cellar, cupboard under the sink and bathroom, I probably have around 4 large IKEA bags full of anything and everything I could possibly want. And this is excluding the stash of polystyrene boxes and fish bags for when I move house.
Just today, I made use of bleach, spirit vinegar, microfibre cloth, cotton buds, cotton pads, towel, hydrometer, credit card (and not for purchases!), bucket, syphon tube, water filter, dechlorinator, glass jar, tweezers and four types of prepared, dry fish food (at home, and another four types at work).
  • Bleach is a decent disinfectant, also useful for killing Aiptasia as I found out
  • Old (credit) card is useful for scraping algae off glass
  • Dechlorinator will render bleach harmless, as well as chlorine and chloramine
  • Microfibre cloth won’t scratch the glass of the tank, when wiping off water stains
  • Spirit vinegar is useful for cleaning off salt and limescale stains
  • Towels are great for keeping the floor dry while messing around with water
  • Kitchen water filter is useful for topping up, if I’m too lazy to water change


Cyanobacteria are a gram-negative bacteria which is often classed under algae by fish keepers because of its ability to photosynthesise. It spreads across all surfaces, coating plants in a layer of slimy-looking goo. In fact, the goo may actually feel quite solid, rather than slimy. There are many different species of cyanobacteria, including the Spirulina genus, which is used in the manufacture of some vegetable based fish foods. The cyanobacteria commonly seen in the aquarium are not as useful, unfortunately, often being from a range of species which specialise in nitrogen fixation. Nitrogen fixation is the conversion of N2 into NH3, this may potentially cause problems. Some species of cyanobacteria are also capable of producing cyanotoxins, which may harm fish.

The biggest dangers cyanobacteria poses in aquariums is killing the plants by physically cutting off light and using up oxygen.

Since the plants can reduce the chanced of the bacteria reappearing in the future, it is important to make sure that the plants are not killed off by physically removing as much of the cyanobacteria as possible. The next step is the treatment. There are two options:

  • Blackout: clean off as much bacteria as possible, then cut out all light for at least a week. This method focuses on the bacteria being starved of light and nutrients (as no fish food would be going into the water). It may take a few attempts to truly kill off the bacteria and each attempt should also be followed by removal of any remaining bacteria. A week without food will not harm most tropical fish, so this method is relatively safe and sound.
  • Antibiotics: an antibiotic which acts against gram-negative bacteria may kill the bacteria. This option needs to be considered with care because most medications are harmful to aquatic animals (the extent to which this is the case depends on many factors, including the pH of the water). Some antibiotics which are sold as treatments for fish will also harm the gram-negative nitrifying bacteria.

Given that there are no fish in the aquarium, I decided to try the antibiotics method. A quick search on the internet showed me that eSHa 2000, a generic antibacterial and anti-fungal medication which is produced by eSHa Labs, may work against cyanobactria. A further search showed that the ingredients are ethacridine lactate (antiseptic, trade name Rivanol), proflavin (antibacterial against gram-positive bacteria and antiseptic), Cu2+ (antimicrobial) and methyl orange (mutagen). Since I was unable to find whether the ingredients acted against gram-negative bacteria, I emailed eSHa to ask. This is the reply I received:

eSHa 2000 does work against [gram-negative and gram-positive] bacteria but not against all bacteria.

Kind regards,
eSHa Labs

I proceeded with a standard treatment, following the instructions on the medication. On the first day, I added 14 drops, followed by 7 drops on each of the following days. By the second day, most of the bacteria was gone. It has now been one week and there are no signs of cyanobacteria left, so I can conclude that the medication or some other combination of factors have resulted in successful treatment.

Sinking the wood

A friend of mine told me that his red moor wood took 4-6 weeks to sink, so I decided to give mine a little helping hand by placing a fish-bag-full of inert rocks on top of it, after moving it into position. On my second attempt, about a week later, I was able to remove the bag of stones, with the wood not floating up. I took the opportunity to move the weeping moss onto the wood, rocks and all included, as it is best when grown hanging off branches.

Keyhole eggs still there..

Cleithracara maronii (stressed colouration)This is quite surprising, but the keyhole eggs are still on the bit of wood and the parents are doing a good job of keeping the snails off! There are a few infertile ones, but most seem to be doing well.
Photo shows one of the other males which wandered too close to the breeding pair: he tried to have a closer look at the eggs, and the pair were not having any of it.

Wood fungus/bactria

Wood fluffThe wood has started growing a layer of what could be either bacteria or a fungus, which is apparently common in aquariums with a higher pH. I have seen this happen on a re-used piece of mopani wood before: it usually stops growing the fluff after a while. Without analysing a sample of the fluff, it would be impossible to find out if it really is a bacteria or a fungus. I took the wood out of the aquarium and washed it off. The fluff feels slimy to the touch, but is harmless.