Absentmind's Red Sea 425 (91 gallon) reef build

[Absentmind8868]

Hey all.

 

New here to WAMAS and have yet to make it to a meeting. A bit about me - I am a recent law school graduate now living and working in D.C. I could not make the summer meeting because it was the weekend before I took the bar (fingers crossed I passed)!

 

I started keeping fish tanks when I was four, graduating to a saltwater mixed reef (primarily LPS and softies) in high school. I had made a deal with my mom that if I could come up with the money, she would let me keep a saltwater tank in the house. A summer of playing competitive poker/blackjack at scout camp later, I made enough money for a 75 gallon tank.

 

I kept a nano tank for a couple of years in undergrad but ultimately broke it down because I was moving too much to justify the hassle. Now, 8 years later, I have graduated law school, found a job and apartment I like in the city, and am ready to put down roots and set up a tank.

 

Now on to the actual tank details:

 

After doing a fair amount of research, I opted for the red sea G2 all-in-one series. I like the look, and red sea has some pretty great reviews on the individual parts. The new system also beefed up the seams, added seam protectors, etc. to deal with the tank failure issues in the original series. I also went to every LFS in the area, and I really appreciated Reef Escape's customer service, timeliness, and attention to detail. They primarily run red sea, so having the LFS connection was enough for me to choose over waterbox.

 

Tank:
91 gallon display, 24 gallon sump

dimensions: 48" x 24" x 22"

lights: reefLED G2 115 (the par readings on these guys are incredible) 

powerheads: 2x ReefWave 45s + return pump

sump pump: ReefRun G2 600

Skimmer: RSK DC 600

Temp: 2x 200w BRS titanium heaters on inkbird

sump light: AI (that'll convert to refugium light once up and running)

reef matt 500

red sea ATO

4x red sea doser (not running yet but calc/mag, alk/pH, iodine/K, iron/trace)

 

As you can see, while I mounted everything on the slideout control panel, the wires are a rat's nest. My next project is to sort this out some (any recs would be appreciated).

 

 

I also have some extra rock in the sump to help cycle that I will replace with a fuge once the tank matures more. I'll also say synching all the RedSea equipment to the app was a PITA, but, after 4 hours of finagling, the one-stop app shop is quite convenient.

 

 

The tank has been fully set up for about 24 hours now. The aquascape is nowhere near done. The goal is to have two main rock structures that larger fish can swim through and a couple of small ones near the sand bed.

 

 

It took a while for the tank to arrive and for me to put together the component parts, so I opted to cure the rock and then cycle it while I waited. Hence, I am doing aquascaping after the initial setup. Tradeoffs, I suppose.

 

 

The tank is still cloudy after adding the live sand, and I need to even the sand out more in the back. I opted for a 1.5 in sandbed so that I could keep wrasses. I also have an aquarium lid I will DIY soon.

 

Water Chemistry:

Salinity: 1.0255

pH: 8.2

Alk: 9

Ammonia: .1 ppm

Nitrite: 1.0 ppm (yikes!)

Nitrate: 7.5 ppm

 

I used Dr. Tim's to kickstart the cycle and have been adding ammonia as it processes through the tank. Hoping the tank can process the nitrite quickly - I would love to start adding fish before too long. I cured the base rock for 3 weeks in RODI water and have been cycling it for 3 weeks in salt.

 

 

Goal is for an sps dominated mixed reef tank. Not looking to do mostly super crazy, slow growing acros, but I want the option and the equipment to keep up with the tank needs.

 

Planned fish stock list (recs welcome):

- ocellaris clownfish pair

- goby and pistol shrimp pair

- cleaner shrimps

- melanurus wrasse

- royal gramma

- flame hawkfish

- bluehead fairy wrasse

- kole tang

- coral beauty angelfish

- small shoal of disbar or bartlett's anthias (add autofeeder)

- copperband butterflyfish

 

it's a heavier stocking plan, but I think it's a good mix of water column dwellers so that everyone gets along.

 

Anyways, I can't wait to post progress pics as I go, and I always appreciate substantive feedback. LMK what y'all think.

 

 

 

 

 

 

Edited September 16, 2025 by Absentmind8868
grammar and to add tank dimensions

[ParrotFish]

Welcome in!! Glad to have ya! Fingers crossed for those bar exam results. When will you get them?

 

Glad you found ReefeScape already as they are solid folks over there. 

 

With the goby/shrimp pair I would recommend having your rocks on the glass and then sand as much as possible. They will dig till they reach the bottom (I know mine have) and can easily disrupt rock formations. Given you are doing 2 mounds of rocks you should be able to, if you decided of course, move the sand over, put the rocks down, and then move the sand back over, and repeat. 

 

Looking forward to your build!

[gastone]

Welcome to WAMAS.  Looking forward to the build and to meeting you in person.  

 

Garrett.

[YHSublime]

Welcome, looking forward to seeing you build out. I really like the Red Sea tanks, but the seam issue was enough to drive me to the Ultum Nature Systems reef builds instead. Glad you did some research first, a second "Reef Escape is great" bump from this guy! 

 

I'd caution against a copperband. I've yet to see long term success in captivity. Just my 2c on CBB's. Outside of that, I'd say it's a pretty solid stock list. You'll might get pushback on the kole in a 90 gallon, but it's kinda silly to nitpick over a 4' tank vs. a 6' tank when we're keeping things in a glass box anyways. Didn't mean to bring all my hot takes to your build thread, but here we are! 

 

Lastly, I'd absolutely invest in a lid, especially with wrasse. I love the look of rimless tanks, but I'd venture to say most of your wants on that list will try to carpet surf. I've intentionally kept my fish list simple because I don't want to ruin the aesthetic of a rimless, but just a few months ago I lost the male of my clownfish pair to a deadly dive. I've had the pair for over a decade and kicking myself a bit. 

[Absentmind8868]

On 9/16/2025 at 3:47 AM, Squishie89 said:

Welcome in!! Glad to have ya! Fingers crossed for those bar exam results. When will you get them?

 

Glad you found ReefeScape already as they are solid folks over there. 

 

With the goby/shrimp pair I would recommend having your rocks on the glass and then sand as much as possible. They will dig till they reach the bottom (I know mine have) and can easily disrupt rock formations. Given you are doing 2 mounds of rocks you should be able to, if you decided of course, move the sand over, put the rocks down, and then move the sand back over, and repeat. 

 

Looking forward to your build!

Thanks so much! I find out in mid-late October.

 

100% agree on rocks on glass. It's hard to tell in the photos, but I am using base rock on all the rockwork. I mostly like the aquascape now, but Iworry the two structures are too similar in height. I don't think this will be a problem once corals are growing on them, but it is something I've noted. Something to worry about or ok?

 

[Absentmind8868]

On 9/16/2025 at 2:00 PM, YHSublime said:

Welcome, looking forward to seeing you build out. I really like the Red Sea tanks, but the seam issue was enough to drive me to the Ultum Nature Systems reef builds instead. Glad you did some research first, a second "Reef Escape is great" bump from this guy! 

 

I'd caution against a copperband. I've yet to see long term success in captivity. Just my 2c on CBB's. Outside of that, I'd say it's a pretty solid stock list. You'll might get pushback on the kole in a 90 gallon, but it's kinda silly to nitpick over a 4' tank vs. a 6' tank when we're keeping things in a glass box anyways. Didn't mean to bring all my hot takes to your build thread, but here we are! 

 

Lastly, I'd absolutely invest in a lid, especially with wrasse. I love the look of rimless tanks, but I'd venture to say most of your wants on that list will try to carpet surf. I've intentionally kept my fish list simple because I don't want to ruin the aesthetic of a rimless, but just a few months ago I lost the male of my clownfish pair to a deadly dive. I've had the pair for over a decade and kicking myself a bit. 

 

Understood on the copperband. He is my stretch fish, and I have been researching the special diet and care needed (building a few low flow zones for him in rock structure, will have clams on the shell, etc.).

 

Absolutely on the lid. I have the red sea DIY lid kit. I just need to put it together. Great catch, especially with wrasses on the stocklist.

 

[Absentmind8868]

On 9/16/2025 at 11:01 AM, gastone said:

Welcome to WAMAS.  Looking forward to the build and to meeting you in person.  

 

Garrett.

Thanks so much, Garrett. Likewise - see you in November? -Mason

[ParrotFish]

1 hour ago, Absentmind8868 said:

Thanks so much! I find out in mid-late October.

 

100% agree on rocks on glass. It's hard to tell in the photos, but I am using base rock on all the rockwork. I mostly like the aquascape now, but Iworry the two structures are too similar in height. I don't think this will be a problem once corals are growing on them, but it is something I've noted. Something to worry about or ok?

 

Maybe making one slightly higher or lower. And that would give you some variation and also slightly different coral placements. I hope that makes sense haha. I like the arches/caves through them though! 

[Absentmind8868]

Hey all! Doing the tank update:

 

Things are going pretty well.

 

The downsides:

 

- I had two occellaris clownfish to start in the tank. Both were happy and healthy for the first week, and then the first inexplicably died (presumed - missing). The second looked happy and healthy (attacked my hand when I'd work in the tank). Then, 12 hours later, it too looked on death's door. Gaunt belly but no signs of an outward parasite. I pulled the second out and did a freshwater dip (nothing came off) and moved to my refugium, but it passed within six hours of the move. I had not added new fish in a week when the clownfish started passing, and all the other fish in the tank present healthy, feed aggressively, etc. etc. After a couple of weeks of no new fish and no fish deaths/issues, I decided things were okay to add additional fish. My best guess is either an intestinal parasite or an infection from the pistol shrimp hitting them caused their deaths, given a lack of issues elsewhere.

 

Current stocklist:

- yasha goby / pistol shrimp pair

- bicolor blenny

- flame hawkfish

- coral beauty angelfish

- cleaner wrasse

- copperband butterfly fish

 

- pencil urchin

- fire shrimp

- misc. emerald crabs, hermits, snails, etc.

- blue squamosa clam

 

 

 

I picked up the copperband and wrasse 48 hours ago. The copperband was eating at the store, and it's tried mysis and some blackworms i've put in the tank. It still isn't going after food strongly, though. That said, it seems to be hunting on the rocks and going after copepods. It is exploring the rockwork some, but it is also overwhelmingly pacing the right hand side of the tank going after its reflection. I am hoping that, with a couple more days, it will go after the food more aggressively. Not sure if other folks have additional recs - I'm soaking in garlic and throwing the kitchen sink in the tank.

 

 

Coral wise, I am dosing 8 ppm calcium and .5 dkh alk a day - still figuring out the magnesium dosing. I also am adding phyto and 10 mL of red sea Coral AB + for the corals and clam. The corals are a mix of sps/lps and some softies. Honestly, my biggest problem is stripping the nitrates as quick as I can add them into the tank. The coral beauty and copperband haven't gone after the clam yet, and I'm crossing my fingers.

 

it'll look crowded quick with so many frags (I went overboard), but I have not lost one yet, and I see some significant growth on the SPS pieces already.

 

 

 

 

 

In any case, I'm quite excited about the next several months. I still have a group of anthias, a bristletooth tang, and a melanurus wrasse left to add. If you all have additional fish recs, let me know!

 

[Absentmind8868]

Also - huge thanks to everyone who has helped with frags, recs, etc. both on and offline. It's so exciting to be back in the hobby, and y'all have made it doable.

[YHSublime]

I’ve had good success with LRS (Larry’s reef service) soaked in selcon to get fish eating. 
 

If it was a disease from the clownfish, it sounds like you didn’t go fallow for long, hopefully it turns out alright. 
 

Consider adding pods, might help the CB in the interim. 

[ParrotFish]

Am I reading things correctly and the tank was only set up approximately 1.5 months ago?

[DaJMasta]

One thing you could try for the copperband is just hiding a portion of the tank - it seems a lot of their initial eating issues is just environmental stress, and I remember an interview with a fish quarantine specialist saying they blacked out the tanks they were QT'd in and rarely had issues getting them to eat.

 

It's my understanding that they don't really go for copepods (mine hasn't), but they do hunt for bivalves and worms (and aiptasia), but that it's looking around is a great sign.  Since they naturally eat off the rocks, it could be worth turning the pumps off for a few minutes and letting food settle.  I've heard using masstick on a clam shell or just feeding frozen halfshell clams can work well, but I think mine first took to frozen bloodworms (this seems to be common for a lot of finicky eating fish.)

[Absentmind8868]

Hey all - sorry for the late reply. New job hit all at once! I meant to come to the fall meeting but got called into work as I was driving over - I will have to make the winter meeting.

 

Thanks all for the comments.

 

I'm still not sure what killed the clownfish, but I strongly suspect internal parasites. Luckily, everyone else seems fat and happy. No losses or unhappy behavior from the other fish.

 

Parrotfish- yup! Tank is about 3 months old now.

 

DaJMasta/YHSublime- thanks both! I ended up getting clams from the market and freezing them to get the copperband eating. After a day or two of skepticism, he started eating voraciously. It took another two days to get him to eat chopped clam in the water column (soaked in vitamins) and then another four-five days to eat frozen from the water column. Now, he's fat, happy, and (still) picky - going for blackworms, the "correct" sized mysis, and clams. Honestly, he is such a fun fish - he eats clam right out of my hand now. Any time I'm in the tank, he's poking around me for food.

 

I added in several species of copepods from algaebarn and am dosing phyto. The glass is teaming with life, and the refugium has plenty of pods, too. Any suggestions on aptaisia in the sump? The Copperband eats any in the display tank, but they are all over my chaeto now.

 

Coral wise - things are pretty great. The acros have started coating their plugs and now don't get knock off by the pencil urchin anymore. I have new heads on the LPS/zoas and new branching on some sps. My milli has covered its rock, which I take as a good sign on tank health. I did lose one hammer to some infection, but the rest are ok! I think I am good on coral for foreseeable future - I want to get more growth out here before I add anything else. I have coraline algae growing everywhere, too, which is cool.

 

 

 

New stock additions:

- 3 bartlett's anthias

- possum wrasse

 

Given my success with the copperband and cleaner wrasse, I shifted my stocking list and would love to get y'all's advice. I think the big concern is strain on pod population, but, if I can get finicky fish feeding on mysis before I add more, I think I should be fine (given pod growth in the refugium, phyto dosing, etc). 

 

Fish to add:

- Bristletooth tang

- neon goby

- leopard wrasse

- mandarin dragonet

- basslet (species tbd on species availability)

- banded pipefish

 

 

Salinity: 1.026

pH: 8.2

Alk: 8.4

Ca: 450

Mag: 1370

Ammonia: 0

N02: 0

NO3: 1-2

P03: .16

 

I was worried about phosphates/nitrates mismatch. But I figure I will keep adding fish to increase nitrates, and I run a small bag of phosphate remover. Looking for stability now.