How should I filter this fish-only marine tank?
I’m very keen on setting up a marine fish-only aquarium. I had such a tank many moons ago. I’ve never really done the coral thing, but I do like the personalities of triggers and marine puffers.
I’m thinking of either a black or a clown trigger in a 1.8m tank. When I kept a Picasso trigger with a puffer about 30 years ago, I had a trickle filter, coral gravel and tufa rock. I did have a lot of problems with red algae, however, although RO water wasn’t such a thing back then.
I wondered if you could advise me on whether one of the above would be more suitable than the other. Should I go for tufa again, or is there a better option these days? And what would you recommend in terms of filtration—plus any advice on avoiding the old red algae? I’m intending on buying salted RO water.
NIGEL TOMBLIN
JEREMY ADVISES: For a fish-only tank I would opt for a sump-based system with a roller filter for mechanical filtration, a large protein skimmer, a phosphate reactor, and a large UV steriliser. Of the two triggers you mention, the clown,
Balistoides conspicillum, is going to become the more aggressive and boisterous, although either would suit your tank and could be mixed with puffers, moray eels, large wrasses, and lionfish.
Tufa rock isn’t used these days as it crumbles and soaks up nitrate, releasing it back into the water over time. Use either ocean rock, marco rock, or any of the man-made, purplecoloured reef rocks that are available.
To keep nuisance algae to a minimum in the main display, use low-powered LED lighting and only have it on for a few hours a day when you are viewing the fish. The ambient room light is fine at all other times.
If nitrate levels in your tapwater are low you could use it along with a dechlorinator and a basic marine salt, although nitrate is the enemy of fish-only tanks, and you will either need to conduct regular water changes to keep it down around 40ppm or use nitratereducing reactors such as a pellet reactor or a macro algae reactor. Salted RO water would be a good choice, however. The roller filter and skimmer will help to keep nitrates down too.
Quarantine your fish or buy from a source that quarantines its fish and try to feed dry foods like large soft pellets as well as meaty foods, such as Krill, prawns, cockles, mussels, and whitebait.