Time for another BIG update
At the end of September I started a new tank - a predator fish only tank. The idea originally was to use the QT tank for this purpose once I had a fully stocked main reef aquarium, but then a couple of things happened that made this unpractical.
Firstly, the QT tank is too small for the fish I actually wanted - the Volitans Lionfish. That fish can grow up to 38cm, and need a turning area of the same width. The QT tank is only about 32cm wide...
Secondly, if I convert the QT tank and one of my fish become ill? And what will happen to the new members of the FOWLR tank since they cannot be quarantined?
Thirdly, and this one I only realised after I purchased the new tank - once you start adding nice predator fish to the tank you want to add MORE ☺
So I got a 400l tank, started it with a deep crushed coral substrate (I want to add some Garden Eels later), and took some of my equipment from the QT tank (such as my Tunze 9015 skimmer). Therefore the tank’s costs itself was limited to the cost of the tank, substrate, salt mix water and new lights. Oh yeah I also added another fluidised sand bed filter for biological filtration.
This was the tank whilst setting up:
The tank to the left is the QT tank.
However as all things aquarium related goes, soon this was not enough. The water temperature fluctuated between 25C (my heater’s set temperature) to 30C in the late afternoon. This was mostly contributed by the 4 x 54W T5 tubes I have in the canopy. So I had to get another chiller (sigh). At least now the tank is nice and stable.
The only thing I would consider adding rather soon is another topup unit. This really makes life MUCH simpler.
In order to stock the tank, I took a bit of a different route. I used a smallish phosBan reactor from the QT tank that had some special ammonia and nitrite reducing media in and placed that in the predator tank. The idea was to move as much of the biological filtration from established tanks as possible. I also added 10kg of LR from my main display tank’s sump. So I now had 10kg of LR and a small fluidised filter for biofiltration. The large fluidised sand bed filter had also been installed and is running, however since it is new it would not immediately add to the biological filtration.
I made 450l of RO/DI water (took 2 days) at SG of 1.022. I mixed the salt in containers for a couple of hours before pouring in to the tank. Once all the water was in the tank I let it run for 72 hours as is.
After this time I purchased my first Volitans Lionfish and Zebra eel. The idea was that since the tank was empty, there was no need to quarantine the fish. If they did show an outbreak of some kind of disease, I could just as well treat in that tank or move them to QT.
I carefully measured Ammonia, Nitrite and Nitrates during the first two weeks. Free Ammonia never went higher than 0.03mg/L NH3 - 10 times lower than the level considered dangerous. Nitrite went up to 0.16mg/L then down to 0 again. Nitrates peaked at 0.443mg/L then went down to 0 again. So the filtration seems to be adequate.
In the mean time I purchased a Leaf Scorpionfish and two frogfish, which went in to the sump of the QT tank. The Leaf Scorpionfish I have since moved to the main predator tank, and the frogfish yesterday. Unfortunately one of the frogfish died this morning. It was the one I purchased with a belly the size of a large marble. I thought it ate something big at the LFS, since it also refused to east whilst in QT.
I thought maybe once in the big tank it would eat better - since it was not diseased or anything. I was wrong. 20 hours after moving to the main tank he (she) died.
The other frogfish seems to be doing just fine.
I also added some 10 Turbo snails to help with the algae that is always inevitable.
3 days ago the tank looked like this:
