View Full Version : 5.5gal CFL-Lit Frag Tank

03/09/2017, 11:34 PM
About a month ago I finally decided to get my feet wet with corals. My main tank is just a FOWLR with no special filtration/lighting, so I set up a really low tech (i.e. low-to-no-budget) 5.5gal frag tank to try my hand at some of the least demanding corals. I went to my aquarium club's annual fragging workshop, where you pay $20 and you get to keep everything you frag, and walked out of there with four acan frags, a finger leather frag, and some sort of acropora frag. I knew the acropora would never make it, but it was free, so I thought, "what the heck." The finger leather didn't make it either. But, the acans are doing well, as I anticipated.

The main feature of this frag tank is that it's being lit ONLY by one 60W (replacing 100W) bright white - not sure on the colour temperature, will check and post back if I find anything - CFL bulb in a desk lamp. Now, the lamp is designed for a drafting-desk, meaning that it has a parabolic reflector to direct all the light downward. I figured that if I was going to try this, I should maximize the amount of light actually getting to the corals. I have the lamp positioned right above the surface of the water, and my frag riack is also quite close to the surface of the water, again so that I can maximize the light on the corals. The frags are all clustered directly below the light source.

Filtration-wise, I just have an AquaClear with carbon, SeaChem PhosGuard, and biomedia from my main tank.

It's been a month and the corals look - to my untrained eye, at least - to be doing very well! I'll post pics another day, for now I just wanted to get this tank started.

The main reason I'm posting this is because I wasn't really able to enough info online about other people trying this to give me any idea of whether or not it would succeed before I started, so hopefully this thread can help someone else who's looking to do what I'm doing.

Next time I'll write up a detailed description of the setup and post pics.

08/26/2017, 01:20 AM
Six months later, I've finally gotten around to writing the first (and, unfortunately, last) update on this tank.

If it wasn't clear from my previous post (I may have mentioned it in another post on the forum), this was intended mainly as an experiment to see whether the acans could survive under one CFL bulb. At the beginning, I was inteding on feeding them coral food, but I had trouble finding any LPS food in my city, so I was using NLS fish food. It became a hassle, so I decided that the experiment would just be to see how the did with only lighting (~8h per day). By the way, the colour of the bulb was "cool white".

Following is a picture of the corals a month after setting up. The two reddish acans weren't super happy because I was overdue for a water change but on the whole they were still all doing super well at that time.


Apparently, in the previous post, I glossed over the fact that one of the acans is actually a platygyra lol. The zoa frag in the centre was purchased a few month after setting up the tank and is the sole survivor.

So here's the tea: Up until six months, things were looking "ok". It was definitely apparent that the frags were not thriving, because their colour was much duller, and they had exhibited virtually no growth, but they were still inflated, at least. Then, within about a week, everything died; when I say "died", I mean that most of the tissue literally just dissolved. As I said earlier, the zoa is still alive and well. At one point it had doubled in its number of polyps, but then when everything else died off some of the polyps disappeared (??).

So yeah... the verdict is that even "simple" corals need more than a CFL bulb to stay alive. If anyone has any specific questions about the experiment, feel free to ask. I ran it with a little more structure than this post lets on, but it definitely was not of lab quality.