Shallow 21 Gal Reef Tank Build From A Beginner

[mh0ward]

Hello everyone! After having considered it several times in the past (even as far back as 12-15 yrs ago), I finally decided to go for it, and try building my own mini reef. The main driver for this, at least recently, was vacationing in Costa Rica and thoroughly enjoying the wildlife there. Since I've worked from home for ~7 yrs, I had two adjustable height standing desks and was really only making use of one of them. So, I wanted to make sure the tank fit the space of the (mostly) unused desktop. Due to the desks footprint, and my want for relatively lower weight and a longer span for fish to swim, I settled on a shallow 3ft wide 90L tank from UNS. This is something I ordered about a month ago, and after receiving it, the first thing I did was leak test it.

 

[mh0ward]

After the leak test passed, I started to look more closely at lighting. I wanted to be sure I had good even lighting and enough output should I decide to try keeping some SPS in the future. Initially I looked at placing a single Radion G6 over the center of the tank, but I didn't like the idea of having no lighting at all should it fail. So, I ended up choosing two AI Prime 16 HDs. I liked the puck style of these lights and the idea that if one failed, I'd at least have one to keep things going while I got a replacement. It seemed like 2 puck style lights would provide a more even lighting than a single fixture as well.

The other aspect of lighting I didn't care all that much for was the available mounting options. For the most part, it seemed like the "best" option was a gooseneck type of mount or something that mounted to the tank itself. I knew I wanted a "clean" look, so I thought I'd try to weld together a mount with square tubing that more closely matched the shape of the tank.

 

[mh0ward]

After fabricating the mount, I took some time painting it with automotive paint and clear. I chose this because I wanted to make sure it would be easy to wipe down and resistant to UV from the tank lighting. With the lighting mount attached to the desk, there would be enough room between the tank and the mount to use a Flipper tank glass cleaner with plenty of clearance. I also mounted a power strip under the desk so that plugs wouldn't droop down, trying to keep the "clean" look.

 

[Gumbies R Us]

Following along!

 

[TX_REEF]

welcome and nice! I love shallow tanks!

 

[kevgib67]

Your off to a good start, following!

 

[parclife]

Looks cool, can’t wait to see how it develops. Good luck

 

[mh0ward]

Thanks everyone! As I said before, I'm a complete amateur at this so I'm anticipating probably needing some advice/opinions in the future

A couple of weeks ago, after getting the lighting sorted, I picked up what I believe is probably Marco rock from the local fish store and started putting together a rockscape. This was probably a little more challenging than with other tank dimensions since it is shallow and limits the options a bit. But, I ended up going with two different low and wide rock formations that would be wide enough that I thought would balance the look of the tank, but shallow/narrow enough that fish could swim around them, particularly toward the front and sides of the tank.

 

[kevgib67]

Thanks everyone! As I said before, I'm a complete amateur at this so I'm anticipating probably needing some advice/opinions in the future

A couple of weeks ago, after getting the lighting sorted, I picked up what I believe is probably Marco rock from the local fish store and started putting together a rockscape. This was probably a little more challenging than with other tank dimensions since it is shallow and limits the options a bit. But, I ended up going with two different low and wide rock formations that would be wide enough that I thought would balance the look of the tank, but shallow/narrow enough that fish could swim around them, particularly toward the front and sides of the tank.

I love it!

 

[mh0ward]

The final result ended up being pretty similar with some minor changes. I also added a small rock between the two, which I think really tied the tank together.

Once I had a rockscape I was happy with, I put each of the pieces in the tank, along with some Caribsea Fiji pink sand... and as is typical, I had a cloudy mess in the end.

 

[mh0ward]

After a couple of days, it cleared right up and now I'm about midway through Dr Tim's cycle!

I've got a Vortech MP10 on the way, hopefully arriving this weekend. Once I get that, it will replace that maxi-jet, which I'll then use exclusively for mixing saltwater. I also had the local fish store hold a bonded pair of clownfish they had so that I can pick them up as soon as the tank has finished cycling and get on with the next mini cycle

 

[Lineatus]

I’m in love with the dimensions of this tank. Excellent choice excited to see what you do with it

 

[mh0ward]

Small update! The MP10 came in on Monday, so I could finally connect everything up and tidy up/zip tie the wiring. Wednesday after about 12 days into Dr.Tims One and Only, the Nitrites had finally came down from something much higher than 5ppm down to 0.5-1.0ppm or so. Just a day or two prior I could dilute 1:5 tank water to clean saltwater in the test tube and would still read 5ppm+ so conversion to Nitrate had accelerated quite a bit over those 2 days. So, I did a 50% water change that afternoon which diluted them down to somewhere around 0.25-0.5ppm and by the next morning was reading zero. Then I picked up my paired clowns and 2 Nessarius snails Thursday afternoon and started acclimating them. After about an hour or so of this, I got them into their new home!

I also found that it is rather tricky trying to capture what the tank actually looks like on a phone camera, particularly with the color, but oh well. 24 hours after adding the fish, Ammonia and Nitrite were still reading zero but I will check again after another day or two. I'm thinking if they still constantly read zero after about a week, I may look at putting a few more smaller critters in and see how that affects things.

 

[TX_REEF]

What a lovely looking system, it’s coming along great!

 

[Patx]

Clean look !

 

[mh0ward]

Another quick update along with some needed advise!

At this point the tank has had livestock in it for 19 days. The first additions to the tank were the 2 clownfish and what I thought were nessarius snails, but as it turns out what I received were Cerith snails - not a big deal.
The clowns were clearly stressed the first day or two - racing back and forth along the top of the tank - but after the second day they settled in and really seem to enjoy their new home now. Their color had even gone from somewhat pale to a much richer orange now!

I had also started a schedule with the lighting and wave maker. The clowns are funny because right around 30 minutes before the lights go completely out, they start to slow way down and are usually sleeping in their favorite corner within an hour It also took a little bit of time to really figure the wave maker out, but once I did, I could make some pretty nice waves at 50% power!

After testing the water a few times through that first week and reading zero ammonia and zero nitrite each time, I added a paired Yellow Watchman Goby and candy cane pistol shrimp, along with 2 more Cerith snails.

They were very reclusive the first day or two but quickly paired up again and went to work on tunneling out under the largest rock (they are sitting on glass). They have a favorite spot toward the back side of the tank, which is still visible from the front, but have also made a couple of entrances right up front.

Not too long after adding these guys, I started to get diatoms on the tops of the rocks and in a few places on the sand. It wasn't too bad but the 4 Cerith's certainly weren't able to keep up, so I dialed the intensity of the lights back a bit and added 2 Trochus snails to help out. After a few more days, they had pretty much cleaned up all of the diatoms so I brought the intensity of the lights back up a bit.... and now a new algae has started to grow that I'm not completely sure of what it is.

It first started to show about 3 days ago and is bright green. It's also much slower growing than the diatoms. I know it isn't hair algae and it isn't slimy. Could it be the start of some Coralline or just some other green micro algae that I'm not aware of?

And now for the needed advice - I have been testing the water every 3-4 days while the tank gets established and this morning when I went to test, I discovered that one of my Cerith's had laid a LOT of eggs.

There must be thousands of them! That squiggly line is 7" long and I'm not sure if it would be best to scrape the eggs off the glass and try to remove them from the tank, or leave them be and mostly end up as fish food? I know I can't have thousands of snails in there! Thanks!

 

[Gumbies R Us]

Another quick update along with some needed advise!

At this point the tank has had livestock in it for 19 days. The first additions to the tank were the 2 clownfish and what I thought were nessarius snails, but as it turns out what I received were Cerith snails - not a big deal.
The clowns were clearly stressed the first day or two - racing back and forth along the top of the tank - but after the second day they settled in and really seem to enjoy their new home now. Their color had even gone from somewhat pale to a much richer orange now!

I had also started a schedule with the lighting and wave maker. The clowns are funny because right around 30 minutes before the lights go completely out, they start to slow way down and are usually sleeping in their favorite corner within an hour It also took a little bit of time to really figure the wave maker out, but once I did, I could make some pretty nice waves at 50% power!

After testing the water a few times through that first week and reading zero ammonia and zero nitrite each time, I added a paired Yellow Watchman Goby and candy cane pistol shrimp, along with 2 more Cerith snails.

They were very reclusive the first day or two but quickly paired up again and went to work on tunneling out under the largest rock (they are sitting on glass). They have a favorite spot toward the back side of the tank, which is still visible from the front, but have also made a couple of entrances right up front.

Not too long after adding these guys, I started to get diatoms on the tops of the rocks and in a few places on the sand. It wasn't too bad but the 4 Cerith's certainly weren't able to keep up, so I dialed the intensity of the lights back a bit and added 2 Trochus snails to help out. After a few more days, they had pretty much cleaned up all of the diatoms so I brought the intensity of the lights back up a bit.... and now a new algae has started to grow that I'm not completely sure of what it is.

It first started to show about 3 days ago and is bright green. It's also much slower growing than the diatoms. I know it isn't hair algae and it isn't slimy. Could it be the start of some Coralline or just some other green micro algae that I'm not aware of?

And now for the needed advice - I have been testing the water every 3-4 days while the tank gets established and this morning when I went to test, I discovered that one of my Cerith's had laid a LOT of eggs.

There must be thousands of them! That squiggly line is 7" long and I'm not sure if it would be best to scrape the eggs off the glass and try to remove them from the tank, or leave them be and mostly end up as fish food? I know I can't have thousands of snails in there! Thanks!

Loving the way your tank is turning out!

 

[LegalReefer]

Leave the cerith eggs, they’ll be good food for your critters. It’s unlikely that they’ll hatch and grow, but on the off chance they do you can take some to your lfs for credit!

 

[mh0ward]

So after a few more days, the lime green algae, whatever it is, is still growing very slowly. I'm hoping it's the start of coralline but I guess I won't know for sure until I start to see some purple.

The Cerith eggs are still there and untouched, so I'm curious to see what happens with them over the next week or so. And, yesterday I picked up a Bicolor Blenny!

This guy got comfortable in the tank much quicker than the other fish and started building a home right where I was hoping - in the other main rock structure opposite of the one the goby and pistol shrimp claimed. He's been fun to watch and seems to have a lot of personality! I had also ordered a Pom Pom crab from the local fish store but it didn't arrive this week, so hopefully next week. I'm also thinking about adding a cleaner shrimp, but havn't made up my mind on that one just yet.

 

[LegalReefer]

Looking good!