BMF’s 120g Comet Reef

[BadMagnificentFirefish]

Hey y’all, this will be my first foray into personally owning a larger reef tank. In my seven years in the reef hobby I have previously kept mostly nano tanks. I did take care of maintenance accounts for an LFS for about a year as well. This time around, I get to have my own!

Here is the equipment list that I have so far.

Tank: Aquarium Masters 120g Reef Ready with single overflow
Stand: DIY currently in construction
Sump: 29g Aqueon with DIY kit from Jax Racks
Return: Simplicity 1600 DC
Protein Skimmer: Simplicity 120 DC
Heater: Eheim Jager 150W x2
Doser: Simplicity
Flow: Jebao SCP-120, Jebao SOW-8
Light: Reefi Uno 2.1 Pro x2

And here is the desired final livestock list.
Blue green chromis x1
Bangaii cardinal x1
Barber pole goby/Tiger pistol x1
Red firefish x1
Royal gramma x1
Ocellaris pair
Carpenters flasher wrasse x1
Fairy wrasse (undecided, but leaning Solon) x1
Lawnmower blenny x1
Mandarin goby x1
Comet x1
I was lucky enough to find a beautiful 1” juvenile captive-bred comet who is currently residing in an established 10g reef with a bangaii and a shrimp goby.

For corals, I have a good number of softies and LPS that will be transferred into the 120g when it is ready. The general theme will be a mixed reef, shying away from more demanding SPS.

Here are some photos of progress so far!

I glued most of the large structures together with the baking soda and super thin CA glue combination, and it has held like a champ so far. The bonds are stronger than the rocks themselves according to some test pieces I broke apart. The structures are currently curing in a saltwater tote with heat and circulation.

The stand is currently under construction. Still need to skin it and add trim, then finish with an esspresso stain and oil based polyeurathane.

The top of the tank is mostly complete. I ordered some 2” wide black acrylic from TAP Plastics and cut it to length to fit the two sides of the tank. Used a Dremel to cut out a few cord holes, and once I get to plumbing, I will make an additional hole for my over the top return. I put some screens together yesterday with 1/8” clear mesh from BRS. Just gotta say, fish jumping deaths are the worst for me. I absolutely hate seeing an otherwise healthy, beautiful fish end up crispy.

Here is Morse, the future king of the reef, in the morning light. He’s just an inch long right now, but is reliably taking TBS pellets. I hope he has a long and happy life.

I am very excited to get this project off the ground, and I will do my best to post updates as the build progresses!

 

[Peace River]

It looks like you are off to a really good start! Morse is beautiful! Congratulations on the new adventure!!!

 

[BadMagnificentFirefish]

It looks like you are off to a really good start! Morse is beautiful! Congratulations on the new adventure!!!

Thank you sir!
Got another work day on the stand tomorrow!

 

[BadMagnificentFirefish]

Made a little progress on the stand today. Visually not too much, but did get plywood on the face and routered to the opening.

 

[BadMagnificentFirefish]

The woodworking aspect of the stand is finished, working on the finish now. Got the wood putty applied and sanded, now moving on to pre-stain.

 

[BadMagnificentFirefish]

Got the stain applied, letting it dry overnight before I move onto the clear coat. I chose Varathane Ultimate Polyurethane, interior oil based clear satin.

For door pull hardware, I found some small brass dive helmets. I think they’re pretty cool.

 

[BadMagnificentFirefish]

Leak test is nearing the third day, everything looking good.
Cable management will be tough.

 

[BadMagnificentFirefish]

Tank is in and wet! Salt is mixing currently. Once the salinity is there, I will add the cured rock structures from my brute tub.

I’ve left shims exposed temporarily so I can adjust them as the tank settles over the next few days. Not worried too much, I put jacks under the joists.

 

[BadMagnificentFirefish]

All the rock and most of the sand has been added! Did 80lbs of CaribSea Ocean Direct, and later I’ll be adding some live sand from Tampa Bay Saltwater. Excited for that addition! Will update photo tomorrow when water has cleared. Running felt socks in the meantime.

 

[Gumbies R Us]

I love how the stand turned out!

 

[Featherweight]

Great start!

 

[BadMagnificentFirefish]

Scape mostly went together how I wanted it to. Helped that the bulk of the structure was already glued together with super-thin CA glue and baking soda.

I know it looks a little short right now, but I wanted to leave a good chunk of room for growth. The top of the left island will be an acro, thinking a classic Bali green slimer, and the right will be a milka stylophora. Those will both put on some height and fill in. The right side of the left island will have some leathers too, a Japanese pink Nepthea and a green sinularia. Those will both grow up a fair bit too.

It’s hard to see from the photo, but there is a lot of cave structure in the left island, plenty of room for a mature comet to take advantage of.

 

[BadMagnificentFirefish]

Tank went through first 2ppm of ammonia in about a week. Added second dose Tuesday evening, will test levels on Thursday afternoon. If the ammonia has processed in that time, I’ll do a WC to lower nitrates, and then introduce some fish!

Morse was out and about today, and I thought for sure he is looking larger. Here are two images of him almost two months apart. He’s definitely growing and changing his spots!

April 29, 2025 above.

June 18, 2025 above.

 

[BadMagnificentFirefish]

Parameters checked out a week ago, so did a small WC and added all the fish from the 10g, a yellow clown goby, a small Bangaii cardinal, a barber pole goby, and the comet. I saw the barber pole only the first day I added him, haven’t seen him since. Everyone else is fine though. All three remaining fish are exploring the new space quite a bit.

Tank is starting the ugly phase, getting some diatom blooms and a little bit of slime. Got some pods and phyto from a local guy in Caldwell, Idaho who cultures them, here’s his website.

Great bottles, absolutely loaded and crawling with pods.

 

[Bohemian Waxwing]

I dig the aquascape

 

[BadMagnificentFirefish]

I dig the aquascape

Thank you sir! Trying to keep the negative space so the corals have room to grow.

 

[BadMagnificentFirefish]

Been struggling with dinos the last week. Haven’t done an ID yet, but I may if they persist. I have measurable NO3 and PO4, so not sure what that’s about.

Today I received my Sand and Rox Box from TBS, 3 lbs of nano premium rock and 7 lbs of live sand. Didn’t get too many interesting hitchhikers, but it was a very small amount of small rock pieces. Everything was fresh and clean smelling though, got some neat coralline, sponges, tunicates, macros, barnacles, and bivalves. Only harmful looking thing was a small whelk-type snail, which was removed. I sorted through the rock in a bucket of clean saltwater, and added pieces with neat photosynthetic things to the DT and sent the pieces with mostly filter feeders to the sump.
I’m hoping the sand had some good worms and brittle stars in it, but it’s a lot harder to tell initially. I sprinkled the new stuff around the DT and mixed it in a little bit.

I’m hoping that the batch of TBS stuff will help boost competition against the dinos. I’ll let things settle in for two weeks, and then see about moving a green chromis from my 10g to the 120g.

 

[Wrassefan78]

Following along, looks great so far. The standard 120 has always been a favorite of mine.

 

[BadMagnificentFirefish]

Following along, looks great so far. The standard 120 has always been a favorite of mine.

Thank you sir!

 

[p1u5h13r4m24]

Awesome! Great job on the stand! I was in a similar situation with always having small tanks, but now I aim for more water volume it really helps with stability and takes a weight of my shoulders