Reefkeeping in an acrylic tank

[mp2022]

Hi all,

I am looking into a tank upgrade in the 100-120 gallon range.

One my biggest concerns is aquarium leaks (which would be a hobby ending event for me from my wife’s perspective) so I am seriously considering an acrylic tank. It seems like no glass tank manufacturer is spared from leaks.

I have read the various posts on this forum and others regarding the pros and cons of glass vs acrylic, so I am familiar with the basics.

I have also seen some incredibly beautiful reef tanks showcased on YouTube that are acrylic.

My question for those who have had long time reefs (including SPS) in acrylic tanks, how much more onerous and cumbersome is cleaning algae off the walls, including coralline algae? I know there are special acrylic specific tools out there. For those that have had success in keeping their tanks clean, how often are you having to clean the walls? Is there any additional tech/equipment that you think has helped? I am assuming a good UV sterilizer.

And in general how noticeable are the scratches that develop from routine cleaning? Do they significantly detract from the aesthetic of the tank?

I am choosing between an IM tank, a rimmed custom tank from Planet Aquariums vs Glass Cages, or an acrylic from Midwest Custom or Tsunami, and am just weighing my aversion to risk for leaks against how annoyed I am going to be with cleaning an acrylic tank and scratches.

Thanks.

 

[lapin]

I think if you clean the sides 1 time a week you should be good. You don’t want coralline to grow. It’s not easy to remove once it gets a hold.
I use mighty magnets with their algae cutter bags.
The biggest pain is cleaning near the sand. Do it last. If you lay something on the sand then run the cleaner across it will help prevent any grains from getting on the cleaner.

 

[UncommonSense]

Acrylic tanks can also be prone to failure in the long-term, though this varies significantly based on build quality, handling, how much heat you expose it to, and how level/well supported it is…

Normal early signs of failure include:

— welded seam(s) starting to separate from stress (white bubble)…

— intense heat on top euro, usually from poorly cooled lights…

— physically cracked acrylic, typically around bulkhead holes… (usually from rough handling)

— substantial stress “crazing” (these are micro-cracks in the acrylic, they can range from superficial to structurally compromising, depending on the scale and depth of the fractures…)


That said, my acrylic hexagon has been in my ownership for over a decade as a reef tank now, and I’m not the first owner!

— scratches are definitely a concern, though they can be polished out if they aren’t extremely deep!

— acrylic is actually more transparent than low-iron glass, so no concerns in that regard!

— coralline is indeed tough to get off… I rely on a plastic razor blade, or a old credit card to scrape stubborn stuff off the walls; the latter is particularly hand in those heat-bent radius corners of the tank where it can be bent to conform!

 

[Tripod1404]

I clean mine around once a week with magic eraser. I also have one of those hand held acrylic scrapers to remove any calcified algae, tube worms etc. to this day, I have no internal scratches resulting from this.

If you get any superficial scratches they are pretty easy to buff off. Internal ones are a little more work, but it can be done without draining the water. Deep scratches are more work (you would need to sand down the panel around the scratch). But you are extremely unlikely to get deep scratches from routine maintenance.

My advice would be not to use magnet based cleaners that you drag across, as if anything get stuck between the magnet and acrylic on either side, it will scratch. I simply dunk my hand inside the tank and to clean it. Just be a little extra careful near the sand.

 

[cycletim]

From my experience acrylic will get scratched its inevitable. It's not a deal breaker for me. My 300 gallon tank is acrylic and I just feel better about it than glass. I have had no luck with magnet cleaners and opted to realizing once per week I have to stick my arm in there and scrub algae. I like to use Magic eraser original. I made sure to get a 24" tall tank as thats the limit of my arm to the bottom.

 

[albano]

From my experience acrylic will get scratched its inevitable. It's not a deal breaker for me. My 300 gallon tank is acrylic and I just feel better about it than glass. I have had no luck with magnet cleaners and opted to realizing once per week I have to stick my arm in there and scrub algae.

I’ve had acrylic tanks since 1988… sanding out a scratch is not a problem (impossible with glass)… but for weekly cleaning, I use the magnets with the acrylic mesh covers/sleeves from Champion Lighting… absolutely the best way to go!

 

[mp2022]

Acrylic tanks can also be prone to failure in the long-term, though this varies significantly based on build quality, handling, how much heat you expose it to, and how level/well supported it is…

Normal early signs of failure include:

— welded seam(s) starting to separate from stress (white bubble)…

— intense heat on top euro, usually from poorly cooled lights…

— physically cracked acrylic, typically around bulkhead holes… (usually from rough handling)

— substantial stress “crazing” (these are micro-cracks in the acrylic, they can range from superficial to structurally compromising, depending on the scale and depth of the fractures…)


That said, my acrylic hexagon has been in my ownership for over a decade as a reef tank now, and I’m not the first owner!

— scratches are definitely a concern, though they can be polished out if they aren’t extremely deep!

— acrylic is actually more transparent than low-iron glass, so no concerns in that regard!

— coralline is indeed tough to get off… I rely on a plastic razor blade, or a old credit card to scrape stubborn stuff off the walls; the latter is particularly hand in those heat-bent radius corners of the tank where it can be bent to conform!

Thanks. Overall do you think that it is less prone to failure than a good, well made and braced glass tank? Have you had both and have a preference of one over the other?

 

[mp2022]

From my experience acrylic will get scratched its inevitable. It's not a deal breaker for me. My 300 gallon tank is acrylic and I just feel better about it than glass. I have had no luck with magnet cleaners and opted to realizing once per week I have to stick my arm in there and scrub algae. I like to use Magic eraser original. I made sure to get a 24" tall tank as thats the limit of my arm to the bottom.

Yeah I am overall leaning towards acrylic. I dont think the scratching will be a dealbreaker for me either - it’s not like I am focusing on the glass when I am looking through the tank anyways. My main concern, mostly because of the amount of negative comments I have heard regarding acrylic for this reason by my LFS and other online threads, is that it will ruin the joy of reefkeeping which for me is building and observing an ecosystem and creating and appreciating the “living art”.

 

[mp2022]

Thanks for all the comments. To be honest, the only real downside I see for acrylic tanks is the scratch issue - but unlike glass these can be remedied. I guess I am just most surprised that acrylic tanks are not more ubiquitous in the hobby for all its benefits, and is what gives me pause, and maybe I am missing something. I guess the other piece to this is that I have a very busy professional life, and while I enjoy tank maintenance, maybe glass tanks are more forgivable if I forget to clean it for a week or two. What I do know, is that if the seams burst on a glass tank and cause tens of thousands of dollars of water damage to my house, my spouse will not be happy….I am sure those folks that got Red Sea tanks thought they were buying a premium product…

 

[Tripod1404]

Thanks. Overall do you think that it is less prone to failure than a good, well made and braced glass tank? Have you had both and have a preference of one over the other?

Acrylic will be less prone to failure overall. But a well made glass tank and a well made acrylic will both last a very long time. A well made acrylic tank can easily outlive the owner.

Acrylic seams are chemically bonded, so it is not possible for water to leak through it as long as the seam was bonded properly. At that point two bonded panels are practically one single panel that cannot detach from each other.

What kills acrylic is the usage of undersized (thin) panels. This cause the longer panel to bow and flex, which stresses the seam two panels are bonded together, and causes cracks. Any reputable acrylic maker will use properly sized panels and brace the tank to prevent this.

 

[UncommonSense]

Thanks. Overall do you think that it is less prone to failure than a good, well made and braced glass tank?

An acrylic tank’s lifespan is predicated by numerous things, but the primary ones would be the quality of craftsmanship, thickness of acrylic used, and general tank shape/dimensions!

Given that Glass Cages can build you a <150G glass tank with 3/4” (19mm) thick starphire glass all around, plus 3/4” thick glass eurobracing and even center bracing… then they can add another 3/8” (10mm) thick stacked layer of glass over the bottom silicone seams inside the tank, and use 3/8” (10mm) glass plus a 1/4” (6mm) acrylic skin for an internal overflow:

I’d say that you can expect a relatively similar lifespan out of either glass or acrylic if money is no object, even possibly leaning toward acrylic lasting longer! (We’re talking multiple decades here)

Have you had both and have a preference of one over the other?

I do have both; my acrylic hexagon, then a rimmed glass 180g, and a rimless glass Red Sea tank I’m frankensteining numerous glass reinforcements into…

It’s a tough internal debate, but at the end of the day, I prefer glass!

— Purely because you can be a bit more aggressive with your cleaning techniques using glass (solvents and metal scrapers can be used with reasonable caution), and because glass tanks tend to offer much larger top openings than acrylic tanks!

— if it wasn’t possibly to modify glass tanks so easily, and cleaning acrylic was a bit less of a delicate matter; I’d be an acrylic fan all day long!

TL; DR: acrylic vs. glass will likely be debated until the end of time, or until some modern material phases both out of popularity… neither one is a bad choice, it’s purely a matter of personal preference! (And I’m lazy, so I prefer easy cleaning!)

 

[UncommonSense]

maybe glass tanks are more forgivable if I forget to clean it for a week or two.

This.

— I can take a fresh window scraping razor to the back wall of a glass tank that hasn’t been cleaned in literally years and make it look immaculate in minutes…

— This technique does require care to avoid scratching the glass, but the fact that it’s possible is a big win in my book!

 

[X-37B]

Any modern glass or acrylic will last longer than most will have it up for lol.
I have 3 IM systems.
I prefer low iron glass.
Past acrylic tanks were nice except most have smaller openings with 6+" of acrylic around the tank.
For me its hard to work in the tank with anything over 3" on a eurobrace.
If I was to do acrylic I would opt for thicker acrylic that allows a 3" euro bace around the perimeter, or even thick enough to be rimless but the eurobrace keeps water in the system and not on the floor.
That would be one sweet custom tank.

 

[mp2022]

Thank you for all the comments. A lot to think about…

 

[ryudo80]

I am in the same boat and thinking about acrylic tank as my next upgrade. Water leakage is my number 1 priority. What type of sand do you guys recommend to minimize sand floating into water during cleaning? My current tank is a waterbox and I have a couple of small scratches even though I thought I was careful with my magnetic cleaner with metal blade. Is the plastic credit card approach really scratch free if no sand is trapped? Also, is a 1/2 inch thick acrylic tank with top bracing good enough for a 6x2x2? I may even go a slightly shorter tank such as 22 inches for easier access inside the tank.

 

[UncommonSense]

Is the plastic credit card approach really scratch free if no sand is trapped?

I’ve been using the credit card trick around once a month for most of the past decade-ish… it definitely gets the job done, and I’ve yet to spot any appreciable acrylic scratches from its use!

The logic here being that wallet cards are typically PVCA plastic, which is softer than acrylic! As long as you keep grains of substrate out of the scraping surface, the card makes a great scraper!

— I‘ve found that using three fingers to bend the card gives you a nice pressure point along one edge to scrape with!

 

[albano]

This.

— I can take a fresh window scraping razor to the back wall of a glass tank that hasn’t been cleaned in literally years and make it look immaculate in minutes…

— This technique does require care to avoid scratching the glass, but the fact that it’s possible is a big win in my book!

Coralline algae left on glass for too long, can etch the glass, and once etched, are near impossible to be cleared/repaired.

Personally, as I have posted many times, I don’t want a glass tank, even for free!

 

[UncommonSense]

Coralline algae left on glass for too long, can etch the glass, and once etched, are near impossible to be cleared/repaired.

Personally, as I have posted many times, I don’t want a glass tank, even for free!

I’ve personally never seen this, and I just helped my LFS scrape 15 years of cumulative life off the back wall of their 180g reef tank a few months ago…

How does this etching occur?

 

[glmory]

Acrylic makes a lot more sense if you don't use sand. I have had very little issue with scratches having reborn media for a substrate. Bare bottom or any other crushed coral would also work fine.

Also, soft coral or FOWLR likely grow less coralline algae so may not be as bad to clean as SPS tanks.

Consider restoring an old acrylic tank as the first step of deciding if you like it. Learning to remove scratches from acrylic when they do occur makes them much easier to live with. Even inside the tank I didn't find them too bad to remove by attaching sandpaper to a magnetic cleaner with velcro.