FAQs on Acrylic Aquarium
Repair and Modifications:
Scratches, Pits, Stress Fractures and Crazing
Related Articles: Aquarium Repair,
Related FAQs: Acrylic Repair 1, Acrylic Repair 2, & FAQs on
Acrylic: Design, Leaks, Drilling/Cutting, Construction, Solvents, & Glass Aquarium Repair,
& DIY Gear 1, DIY
Gear 2, Tanks, Stands, Covers,
Custom Aquariums, Stands,
<.... please send all future petfish corr. to me/us at
I have a 125 gal acrylic aquarium that is about 8 years old. I recently
emptied it out to refurbish my system and noticed some crazing along the
seams (pictures below).
They do not appear to be deep, but do run along the entire seam. Is this
okay, perhaps with reinforcement. Thanks.
<It is IMO/E... may not look nice, but should be structurally sound>
BTW – I love your book. I used it to start my first aquarium. My kids
recently picked it up and started looking at it which led to the
decision redo my system.
<Hey! Don't blame me! Cheers, Bob Fenner>
Used 90 gallon, too much crazing for comfort?
I probably visit your site daily so thanks for providing such a great
source of information! On to my question which I think I know the answer
to, but wanted a second opinion.
So I just bought this tank off CL which is supposedly 2 years old. The
holds water fine and was being used until I bought it. Here is what I
noticed when I got home though (see pics).
I know some crazing isn't that uncommon with acrylic tanks, but does
this tank need support added or am I just being paranoid?
<I would not fill this tank w/o putting in internal corner supports. See
Tank specifics - standard rectangle SeaClear 90 gallon (reef ready) with
two openings on top (euro style?). Unfortunately the tank is 3/8
thickness, but when filled I didn't see any bowing anywhere.
The only crazing is at the bottom seams and a little on the corner. The
top brace seams are fine all around. The pics included are the worst
spots and they were taken with the tank dry. The seam is completely
smooth on the outside and inside when I run my hand along it. So the
"frosty" spots are in the seam itself.
Rest of the tank looks great, just not sure what to make of the crazing.
<Structural weakness. Bob Fenner>
Re: Used 90 gallon, too much crazing for comfort?
Ok thanks for the reply. Kind of what I thought also. This might be a silly
question, but with the reinforced seams is that a very long term fix years)
or a short term (a year) assuming it is done correctly?
Many years (decades) of life to this system w/ the reinforcing square
doweling inserted (solvented) into the corners. I would definitely be doing
this job. BobF>
Surface repair of acrylic aquarium
Hi. I bought this 150 gallon tank and currently have it cycling. No sand
or rocks in it yet (well, in the pic there is one). There is fine
bubbling along the exterior surface of some of the tank. This is causing
some distortion when looking from the side into the tank.
Can this be buffed out?
<Mmm, if quite shallow, yes... Think on the process here: you're
grinding down the areas around... Can the tank be turned around, viewed
from the less-damaged side?>
Thanks so much for any advice.
<Do see WWM re scratched acrylic tanks. Bob Fenner>
|Re: Surface repair of acrylic aquarium
I did read thru that section.
Is what you see in my tank called crazing?
<Mmm, looks more like some sort of external physical damage to me>
You can definitely feel it with you hand. I'm comfortable working with
sanding and polishing equipment (I've refinished
fiberglass kayaks) but don't want to start this project unless I'm certain
what the defect is.
<As you state, could be crazing from too-thin material, perhaps a
non-planar, unlevel stand... There are some good polishes about for the job.
Re: Surface repair of acrylic aquarium
it is also on much of the front of the tank. Almost looks like tiny bubbles
in some places.
<May be imperfections in the material itself>
Sounds like what ur saying is regardless of what it is, if its only
superficial it can be removed with enough TLC. Is that accurate?
Can i send another picture?
<If you think it would help. B>
Re: Surface repair of acrylic aquarium
Another picture of the surface from a slight angle.
<... could still be the same possibilities; bad cast acrylic, crazing...
Re: Surface repair of acrylic aquarium 11/21/12
Well thank u so much for your time.
Re: Surface repair of
acrylic aquarium 11/24/12
One last question if i can. Do u
recommend hand only application of the sandpaper
<I don't suggest the use, ever of such on acrylic>
or can i use a hand held vibration sander?
<Yes, but unless the scratches are huge... like a sixteenth of an inch deep
or so... I wouldn't "do this" period... heat burnishing might be the route
to go IF the acrylic were thick enough. Small encapsulated bubbles in the
material cannot be effectively fixed>
If not, is it fine to use an orbital sander for any of the process,
specifically the polishing?
<It is not>
And i was planning on using Novus products.
<These are good products in my estimation. Bob Fenner>
Re: Surface repair of acrylic aquarium
Started the project. Went as low as 320 grit but those defects are still
there. I did repair a section all the way out to make sure i could do it.
Finish after the #2 Novus was very shiny. However, i was wondering if u have
used as coarse as 120?
<Dangerous... hard to remove the subsequent scratches, and may well remove
too much material>
Seems like i well definitely need more than 320 to do the job. Just a bit
<Me too; having seen so many damaged, destroyed tanks... Have you tried heat
burnishing just a small section? Have you contacted any of the acrylic tank
re-surfacing companies? I've met Matt Conrad, owner of See Clear
acrylicscratchrepair.com , seemed like a nice fellow. Bob Fenner>
Re: Surface repair of acrylic aquarium
Started the project. Went as low as 320 grit but those defects are still
there. I did repair a section all the way out to make sure i could do
Finish after the #2 Novus was very shiny. However, i was wondering if u
have used as coarse as 120?
<Dangerous... hard to remove the subsequent scratches, and may well
remove too much material>
Seems like i well definitely need more than 320 to do the job. Just a
<Me too; having seen so many damaged, destroyed tanks... Have you tried
heat burnishing just a small section? Have you contacted any of the
acrylic tank re-surfacing companies? I've met Matt Conrad, owner of See
, acrylicscratchrepair.com , seemed like a nice fellow. Bob Fenner>
Re: Surface repair of acrylic aquarium
Thank u. I will let u know what i find out.
<Thank you Richard. BobF>
200 Gallon Acrylic Cracks 8/25/12
I was hoping you could give me advice on a few cracks I am seeing on my
first all acrylic aquarium.
<Mmm, yes... stress fractures... quite common>
The tank is 200 gallon and uses 1/2 acrylic (I am guessing this is why
it is cracking). These are the only cracks on the tank, minus some
crazing and I am unsure if they are getting larger. It doesn't
seem like they could get much larger to be honest! What will
happen if the cracks get to the other perpendicular panel?
Is this fixable? Is there a way to stretch the life of this tank?
Thank you for taking a look at this. I cringe every time someone
puts their hands on the tank!
Thank you again!
<I wouldn't worry. Use the search tool on WWM for the string: "Acrylic
stress fractures". Bob Fenner>
Help! Acrylic Scratch Repair Nightmare (a not uncommon tale,
actually) – 07/20/12
<<Hello Dave…(wow - just had a flashback to ‘2001: A Space Odyssey’)>>
What oh what have I done...
<<Hmm…from the pic it appears you’ve been a busy boy>>
The 200G tank I acquired had heavy coralline deposits on the sides, and
a fairly clear front viewing panel aside from two very prominent/large
scratches that ran along the inside. I tried to follow advice given on
how to use a polishing wheel and a rouge/compound to remove the
Somehow the tool got away from me in a split-second, and put a small but
very noticeable gouge in the front display.
<<The use of power tools to remove scratches from acrylic requires some
practice/experience…as you have discovered. Best for the novice to stick
to manual methods of removal (elbow grease), in my opinion. Aside from
the probability of causing further damage “in an instant,” the use of
power tools increases the likelihood of creating a “lensing” effect in
the acrylic…not that the tool is the problem, but rather going back to
the technique/lack of experience of the operator. The last thing you
want after removing all the scratches is to fill the tank only to find
the contents look like the reflection in a fun-house mirror. You can
also cause this sans power tools, but it’s likely to be to a lesser
degree and more easily rectified>>
I searched WWM and spoke with several, and decided to go the sandpaper
route to undo my damage and try to take out the initial blemishes (the
polishing wheel didn't work as I hoped - likely my technique was poor).
<<And the polishing compound you used…more to follow on this>>
I started with a heavier sandpaper, seeing that one kit online included
a 150 grit for "gouges".
I worked my way down and back a few times. At this point, I fear that
the 300 grit gouges don't seem to be coming out with the 400 sandpaper.
Yikes, what have I done!
<<Fear not…this can be fixed easier than you might think>>
Can someone offer any suggestions??
<<Indeed I can…in fact several. Be sure to “wet sand” the acrylic. The
use of ‘water’ helps to lubricate and cool the surface, and float-out
particles. As you move up through the grits (300 to 400, etc.), do sand
“perpendicular” to the scratches made with the previous grit, and until
all the scratches run in the new direction. I also suggest that once you
go beyond the 400-grit paper that you invest in a “quality” sandpaper. I
use ‘Micro-Mesh’… It is pricey but worth it. The “grains” on the paper
(actually cloth) are all equal in size which means no stray scratch
marks, and a very fine finish. Micro-Mesh comes in grits from 1500 to
12000…the 1500-grit Micro-Mesh is about equivalent to 600-grit paper
from the hardware or auto store. You can buy Micro-Mesh on its own (do a
Net search re the name), or get it in a ‘scratch removal kit’…an
advantage to the latter is it will also provide some further instruction
on its use. You can also get kits that allow use with a ‘magnet cleaner’
for removing scratches/blemishes once the tank is up and running (this
is handy…I know). But… Since this tank is empty I am also going to
suggest you look in to the ‘NOVUS’ line of acrylic scratch removers.
This is a “liquid” compound that comes in varying “grits” and works very
well…either with a powered polisher…or by hand>>
This is 3/4" acrylic, so I assume I have wiggle room to get this worked
<<Some, yes…but don’t get excessive…remember that lensing effect I
mentioned. To keep this to a minimum, you will need to increase the area
polished with each successive grit. The use of a ‘wax’ pencil to mark
the areas as you progress will simplify keeping up with this>>
But, I am very worried right now.
<<Can be fixed>>
I assume a power tool is required at this point.
<<Is up to you… But I would suggest this only when/if you use the NOVUS
product…and then, use light pressure (e.g. – let the weight of the tool
do the work), and keep the tool moving. Otherwise…”hand” removal all the
Manual efforts don't seem to be working!
<<This is the best for the initial “heavy” removal…less chance of
error/removing too much!>>
<<I have used both of these products and believe in their quality and
effectiveness. With some patience and a bit of sweat, I think you will
be happy with the result. Keep in mind too that although you can bring
the acrylic back to “like new” with these products, very fine scratches
will simply “disappear” when the tank is filled with water>>
<<Happy to share… Eric Russell>>
Re: Help! Acrylic Scratch Repair Nightmare (a not uncommon
tale, actually) – 08/01/12
Eric, thank you!
<<Quite welcome, Dave>>
Back to a fairly clear tank.
Thanks for the humor/levity, helped set my mind at ease...
<<Was my pleasure…>>
The labotomous fun that amateurs have working against themselves in this
<<Indeed my friend…but you are less of an amateur now, eh! Cheers… Eric
Crazing on bottom of fish tank 7/6/12
I've read the entire section on "scratches, pits, and crazing" but have not
seen anything related to crazing on the bottom piece of a tank.
My TruVu tank is 270g (6'Wx3'D,2'T, 1/2" thick), probably
about 10 years old now. There is a little crazing in the seams but nothing
abnormal and it hasn't changed in the 3+ years i owned the tank. I'm more
worried about the crazing going on the bottom piece. No other pieces have
any crazing and there is very little bowing; really you can barley <barely>
tell it bows at all. Above the stand i have a 3/4" piece of plywood
(no screws or anything just laid on top), followed by 3/4" open cell foam
mat; the puzzle locking kind for kids to play on.
My tank is level from left front to right front and left rear to right rear.
The left front to left back and right front to right back are both off by
1/8" equally. The bottom should be planer as well since i do not see any
parts of the foam mat excessive pushed up against the bottom piece of
acrylic. What makes this even more complicated, is that I do not know if the
previous owner caused the crazing or if i did. I just noticed it recently
when i removed the gravel. I'd like to add some new/different gravel
now but worry i won't be able to keep an eye on the crazing. This is a big
risk since the tank is
sitting in my living room. Oh yeah, i also reinforced my living floor so it
shouldn't be causing any twisting to the stand/tank.
Thank you for your time,
<I don't consider that there's a real problem here. Some such crazing does
"happen" w/ much sheet nowayears... not a structural issue... and you have
good support underneath. I wouldn't worry. Bob Fenner>
Acrylic 5 gallon tank 6/25/12
I got a used 5 gallon hex tank for $5 the other day. I figured I can't
lose with that. The hood is great, but when I cleaned and filled
up the tank, it was cloudy all over.
<Have you looked down from the top? Is the water cloudy or is the
I thought it was just condensation, but it isn't. The tank may be 20 years
old, I don't know, but is this what happens to acrylic tanks when they
come to the end of their lives??
<May have been caused by what you cleaned it with.>
<You're welcome. James (Salty Dog)>
Re Used Acrylic 5 gallon tank 6/25/12
It is hazed when it is filled with water. I emptied it a few hours ago
and it seems to be slowly clearing from the top down. If that is hazing,
what causes that?
<Ammonia based cleaning products such as Windex can cause that.>
Does that mean the tank is useless??
The only thing I used on it was a 3000 grit sponge to clear the
<You may need to wet sand with that sponge in a circular motion.
This is called polishing is the last stage in cleaning/restoring
acrylic. You may also need to clean/polish the outside of the tank
before it will appear clear.>
<You're welcome. James (Salty Dog)>
crack in bottom of bowfront glass
tank, & crazed acrylic one
I've been reading your posts for a really long time but
thanks to your specific answers never needed to ask anything
until now. I have been reading tonight about cracks in tanks, but
this tank was given to me free and it looks brand new. The people
I got it from never used it and possibly the people who gave it
to them might have, but again it looks new, my guess is it
cracked when they tried to move it downstairs. It appears to be
about 46 gallons and the crack is in about the right third front
bottom piece and about 2" long starting with what appears to
be a chip and then branching out thinly. I've read where you
say to solvent a piece but not clear on whether to put the piece
over the bottom piece or under it.
Also, I've heard to use aquarium sealant first on the crack
and then whatever you recommend to adhere the extra piece. Would
you recommend just sealing it to the joints or sealing it to the
actual piece all over and the joints?
<Over all is best in one go... NOT sealing the cracked area
And what specifically should I use if I need to seal the crack
first and then adhere the other piece.
<Glass or acrylic... aquarium-safe Silastic. Posted on
Sorry I'm sure you've covered this somewhere but
with 2 little ones at my heels I don't have days to read it
<Maybe get some help w/ this project>
Oh, also, I got a 55 g acrylic off craigslist of course and after
filling it noticed that where it bows on the front bottom half
there are lots and lots of what look like stretch marks that go
in the shape of the bow like a rainbow shape,
<Crazing... see WWM re>
I had fish in it for 2 days but freaked that it would break. I
attached a pic, but not sure if it's worth saving.
<Not an uncommon occurrence... w/ cheap/er acrylic, improper
support... Bob Fenner>
Re Acrylic aquarium crazing?
I have discovered the tank has 1/2" acrylic, a 14" strut and
4" lip around 2 cutouts on the top. The cutouts have right angle
edges, not rounds, and there is only slight whitening along the seams
of the tank (front to side panels, etc).
In all, this seems a good health bill, except I'm worried about the
right angle edges for the cutouts on top (versus having rounded
Does any of this change your guidance?
<No. What are your concerns with the right angle cutouts?>
Again, very appreciated,
<Welcome. James (Salty Dog)>
Re Acrylic aquarium crazing? 2/13/12
I was worried based on the article about acrylic tank repair
(http://www.wetwebmedia.com/acrylicaqrepair.htm) that mentions the
benefit of rounded corners for the cutouts. Since it doesn't have
this (i.e. it has the right angle cutouts), I wondered if I should be
<Since the tank has been in use and hasn't cracked yet, I
wouldn't be too concerned unless these right angle cutouts were
close to the two large openings. And yes, holes etc made with a hole
saw or router would be better to reduce stress.
Is it possible to take a pic of the top of this tank and send to us?
James (Salty Dog)>
Re: Acrylic aquarium crazing? Ammoniated cleaners?
Yep, read it myself. As you know age also will cause this depending on
the type of acrylic used.
<... the citation? Not your assertion. WHERE did you read this, can
anybody read this? I've been under the impression that most crazing
was a sort of "stress-fracturing">
Q. Ho do you clean acrylic sheet?
A. Use a mild soap & water mixture with a gentle cleaning cloth. Do
not use ammonia based cleaning solutions on the acrylic as it will eat
into the sheet and cause it to craze.
The source was http://www.plaskolite.com/faq.htm
<This is their general FAQ site... Where specifically?
Re: Acrylic aquarium crazing?
The FAQ section here. Scroll down a bit.
<Ahh, I see it now:
"Q. Ho do you clean acrylic sheet?
A. Use a mild soap & water mixture with a gentle cleaning cloth.
Do not use ammonia based cleaning solutions on the acrylic as
it will eat into the sheet and cause it to craze. "
<Thank you James. BobF>
You're welcome Roberto.
Re Acrylic aquarium crazing? And now leveling 2/20/12
Salty Dog (or other Crew),
THANKS for the help here.
I ended up buying and setting up the tank. I compared pictures of the
top of the tank to pictures on your site, and can see it has slightly
rounded edges on the cutouts, fortunately. I also see no signs of
stress. The crazing seems to all be cosmetic, which has been confirmed
by the aquarium mover (also has acrylic tank manufacturing operation
here in town). As it turns out, it is only 3/8 acrylic, but as there
are no signs of stress for this tank (135g, 60" x 20" deep x
24" wide), it seems I am ok.
My final concern with the setup is whether the leveling could be an
issue. From front left to front right, the water line drops 1/8".
From front left to back right, the water line drops 5/8" (or could
Seems I have an issue that must be resolved by draining the tank and
shimming (sigh). The concern I have with shimming is that the acrylic
stand does not have 4 legs, but a uniform base that contacts the floor
at all points.
<That's not a big problem. Use full length shims under the base.
If you have, or know someone with a table saw, you could rip full
length shims to the thickness desired. I would not use plywood for
this, especially if on a carpet. The glue could transfer to the carpet
and stain permanently.>
Would you agree that this leveling is an issue, and if so - do you have
any suggestions with managing it?
<My main concern would be if the tank has a slight twist in it due
to not being
plumb. It's always a good idea to put 1/2" Styrofoam sheeting
between the tank and the stand which
helps prevent any twisting. Another issue is that if this tank has a
built in overflow and with the water level being low at the rear, your
front water level may be at the top of the aquarium. If not, I'd
leave it alone barring any twist in the tank. James (Salty
Re Acrylic aquarium crazing? 2/21/12
Salty Dog: Thanks...huge help...
<You're welcome Dave.>
I did some more tank inspection and WWM research to make sure I
understood tank twisting issues you had concern about.
I measured the stand, and see that it has the same exact level issues
as the tank. Taking level measurements around the carpet areas
surrounding the tank seem to be close to the tank/stand measures. So,
seems that I have a floor (concrete slab under carpet) leveling issue.
If I understand your comments, this may not be as much of a concern at
these difference (i.e., biggest slope causes 1/2"-5/8"
difference between back left (higher) and front right corners of tank),
therefore it may be wisest at this point to just observe for signs of
tank stress (such as pronounced further crazing in front right corner)
but not drain/shim?
<By your comments it does not sound like there is any twisting going
If the water level isn't visually objectionable, then I'd leave
Also, water level does not touch the top of the front right corner of
the tank. It i 1/4" below top (which I took into consideration in
<Good. James (Salty Dog)>
Acrylic aquarium crazing? 2/13/12
I have researched for enough years on your site, and finally
today have placed a 50% deposit on a tank to begin my dream
aquarium. Now, a few hours later, I am panicked as to whether I
made a mistake.
I looked at a 130 gallon 60"l x 20"d x 24" h
acrylic tank today. The current owner had it for 10 years, and
acquired it from a restaurant that owned it for an unknown time
period. I took pictures of the tank, and noticed what I later
confirmed to be crazing throughout the front panel. Please see
the attached pictures of the tank. In one picture, you can see
where the flash captures the crazing - this pattern was
throughout the front panel (although they seem to be minor and
parallel to the floor). In another picture, you can see where the
flash seems to have caught corner crazing.
Unfortunately I did now inspect the corner seams, top, or front
(for bowing) closely. Do you think the visible crazing is bad
enough for me to abandon my deposit?
<Crazing is generally caused by cleaning acrylic/polycarbonate
with window cleaning fluids such as Windex.
<<Really James? RMF>>
As far as functionality goes, you should be fine here and the
crazing will tone down once water is added. If the price is right
and the crazing isn't objectionable to you, go for it. Might
want to read here.
<You're welcome. James (Salty Dog)>
Clarity Plus Lifetime Warranty? (and acrylic tank
resurfacing/repair) -- 01/07/12
I have recently purchased a 300 gallon acrylic aquarium from c-list for
a couple bucks and thought I was getting a real deal.
<<Mmm, is often the case'¦till one sees the scratches.
But even so, this can still be a 'deal' if you're willing
to apply some elbow-grease. Returning the tank's clarity is not all
and I may have if I don't count for my labor resurfacing the
My question is and it's a three part'er; how would one go about
contacting the aquarium manufacturer being Clarity Plus (SeaClear, the
Casco Group and so on) to attempt to cash in on said warranty?
<<If this tank has been modified or repaired (other than
authorized) in any way, it's likely the warranty has been
I cannot find any contact info for them anywhere. Wondering if maybe
they shut their doors?
<<Hard to say'¦their products seem to still be on offer
though. You might try contacting a retailer selling their product, such
Assuming I am not lucky enough to cash in on that warranty and continue
doing the work myself, how clear is clear enough for acrylic?
<<'¦? You would be surprised at what
'disappears' when water is added to the
I have dry sanded from 120grit up to 400grit and then wet sanded from
400-4000grit and come back with polishing compound and have gotten it
<<This is likely sufficient'¦adding water will
However there still appears to be distortion from a few feet away.
<<Mmm'¦ This is from not sanding 'evenly' across
the entire surface of the panel'¦or at the least
'feathering out' the perimeter of the sanded areas. Failing to
do so creates what is called a 'lensing effect' and results in
the distortion you are now seeing>>
I can place a book inside and still read it but can't read it
looking through both panels (just a test for clarity no intentions of
<<Indeed'¦kind of like trying to read through two
stacked glasses lenses>>
Is the distortion because I boogered-up the restoration process on the
<<A likely scenario>>
or because the tank has some age and permanent-bowing to it?
<<A less likely scenario>>
Am I worrying to much and water will fix it?
<<Possibly'¦I would test and see'¦is possible
the lensing effect is not that noticeable/within acceptable viewing
(have not finished the resurface part yet to retest clarity with water,
but don't want to waste my time if its going to look like poop)
The seams of the tank in various places around the tank have turned
whitish in some spots. Almost like there is frost or ice between the
panels. None are very large maybe 2' at the most , but they do span
the whole 1/2' of acrylic. Never owning an acrylic tank I don't
know the risks involved.
<<Minimal'¦but again'¦a water
It would be my assumption that the chemical bond broke there just
isn't leaking (have done a 2 week leak test with litmus paper on
the seams to verify leaks).
<<Then you likely don't have a worry re'¦but while
the tank is empty and dry you can easily beef-up these inside corners
with triangular acrylic doweling>>
Do these need to be shored up with the square braces as suggested in
other posts or can I take a needle with solvent and forces it in the
joint? Or something along those line?
<<My choice would be the acrylic doweling'¦applied very
carefully; to avoid any further marring of the viewing surfaces, with a
'thickened' acrylic solvent like Weld-On #16 or Craftics
Any and all answers and suggestion will be greatly appreciated.
<<I hope I have served>>
<<Happy to share'¦ Eric Russell>>
Re: question regarding 330g acrylic
Help appreciated: 300 gallon acrylic crazing (is it
Hi guys! I just bought a 300 gallon acrylic tank from a Chinese
restaurant that was closing down. The tank is 10 years old and
appears to be in relatively good shape. The acrylic is on the
thin side (only 1/2" on all sides). The tank was running
when I bought it and to my knowledge it had only been setup once
(and then safely moved by me).
Ok, so the owner scratched the heck out of it and I have started
sanding and polishing it (not so bad actually). My concern stems
from the bowing and crazing on one of the main panes. After I
purchased the tank and started taking it apart, i noticed a
pretty significant bow, maybe 1/2-1" in the center of the
tank. I did not notice until I started cleaning it that along
this bowed side there is some crazing. It is very minor looking.
In picture one you can see the craze... below the crazed area is
a tiny craze that has formed a small crack (2mm) that is visible
from all angles. There are probably 4 of these little cracks but
you can not feel them with a fingernail yet so I'm not toooo
worried about that yet. The light, hardly visible crazing runs
along the entire length of the tank (Picture 2). It is only
visible from certain shallow angles. What do you think?
<That eight megs is too many>
My next concerns come from the cutouts.
There are 3 cutouts on the top of the tank. The person that cut
them did a terrible job. They were cut by a jigsaw of some sort
and the perpendicular cuts intersect on almost every corner (see
Whoever it was also tried to round out the corners but didn't
do it well at all. While it is common practice to round off the
corners, do you this this is an issue (should i bother round them
Picture 6 shows the second worst crazing on the top panel but
most of the imperfections seen are surface scratches... None of
the two (side) cutouts have any crazing stemming from the
intersecting cuts. However, the middle cutout has some crazing
along the strut. Picture 7 shows the strut crazing which travels
lengthwise. Do you think I should Weldon a 1/4" sheet on top
of this spot to combat bowing and help out with the crazing?
My last question has to do with 2-3 bad points in the seams.
They are both on opposite corners of the tank. The one in picture
8 is about an inch long and the one in picture 9 is probably
The seams are in very good shape otherwise (minimal crazing and
no bubbles). Please give me your advice on this tank. Should I
add 2-5" triangular dowels along these weak seams?
Should I add sheet of acrylic on top of the strut?
Should I round the corners of the cutouts? Is the crazing on the
viewing panel of the tank an issue? What would you do here? What
wouldn't you do here? And have I asked too many questions in
<What would Deuce Bigelow say? "Well, then you paid too
I have been struggling to find any local shops specializing in
acrylic aquariums. Please let me know what you think.
I love you guys! Thanks! ~Abe
<You've got what you've bought. Enjoy it. Bob
thank you so much. I just went and looked at the 330 acrylic. One last
question; there a many scratches visible on the inside
of the aquarium. Most are about the width of dental floss. Could I buff
these out without further damaging the acrylic?
<Yes; please read here re: http://wetwebmedia.com/acraqscratch.htm
Not nearly as visible when the tank is filled>
The tank is pre-drilled with 2 overflows, one in each corner (2 holes
each). I asked for the manufacturer but the couple selling it only
knows the LFS they bought it from (pretty reputable in ATL). They are
asking $1,500 but they are admittedly willing to take a reasonable
Would getting this aquarium (with moderate scratching) for around
$1,100 be a reasonable price, in your opinion? Nothing else is
<Seems a bit high still... I would start considerably lower>
BTW, your 2nd edition Conscientious Marine Aquarist arrived this
morning... time to read!
<Know the author. A fine fellow>
Is this tank with crazing and scratches
safe to use? 8/4/11
Hi! I have been reading quite a bit on your site and have found
much useful information. Thanks so much for that! Even after
reading through your acrylic pages, I am still unsure about this
used tank that I have. I has many scratches and I am pretty
confident that with time and effort I can get those out. My
concern is the crazing. I'm afraid that I just don't have
enough confidence in my own judgment to decide if this tank is
going to hold water for the long haul. I have read that tanks
with crazing can still last many years. But, I have also read
that some people wouldn't trust them. I have included some
pictures. The crazing is present along the bottom edges on the
side panels and a little on the front panel. There is also some
crazing along the top edge and this is also on the side panels.
The front panel has no crazing across the top. Before I put all
the time and effort into removing the many scratches, I was
hoping to get your opinion as to whether this tank is even safe
to use. Thanks so much for your site and your anticipated
<You will likely be fine here functionally. And with water in
this tank, the crazing will be much less obvious. Bob
Removing Paint from an Acrylic Aquarium --
I am looking at purchasing a used 55 gallon Hex acrylic tank that has
one pane spray painted black.
I would like to remove the paint so the aquarium can be put in the
center of a room. The owner said he used black spray paint. Can the
paint be safely removed from the acrylic, and if so, any suggestions on
the best way to try this?
<<I can't think of any way to remove the paint that won't
damage the 'clarity' of the acrylic. Solvent paint strippers
(Citric Acid based or not) will likely cloud the acrylic -- and of
course, sanding the paint away will obscure the view as well. The good
news is the acrylic can be polished to return the clarity of the
viewing pane. And this is easier done than many realize. If it were me,
I would 'carefully' wet-sand away the paint (use the finest
grit that will remove the paint) versus a solvent paint stripper, as
any 'clouding' from the stripper may go deeper in to the
acrylic (in some situations, this may even penetrate the full
thickness) than any light sanding scratches. Once the paint is gone,
it's a simple matter to sand and polish the acrylic back to its
original clarity. Do a NET search re 'Acrylic Scratch Removal'
for kits and supplies. There are both 'liquid' and 'sand
paper' type products for this -- my preference is to use the paper
(called 'Micro-Mesh') first, and then finish with a liquid
polish like that offered by 'Novus' - just follow the
manufacturer's recommendations. You will also find there are kits
available for use with power tools, but for a small project like this
-- and as a first-time user -- the ole' 'elbow grease' kits
will serve you best>>
<<Happy to share'¦ EricR>>
how to inspect a used acrylic tank. 11/7/10
I have found a 300 gallon hexagon acrylic tank, wood stand, and acrylic
sump for sale that I am considering purchasing. The seller says neither
have been used, and have been in storage since 2001. The seller said
they were to be used in a project that he could never find the time or
money to get started, and now wants to sell because of financial
problems. Not sure about the explanation, but who knows.
This would be my first acrylic aquarium purchase, and wondering how
exactly I should inspect the tank and filter, to determine if they are
in fact unused, if there are any defects, and if the tank can function
as a show piece in my living room.
<Mmm, well... close to best/better is/would be to fill all up and
check for leaks, that all gear is functional. In fact, pump/s,
lighting, filtration are likely to be "dated"... Do you
know/trust someone who knows what they're looking at to inspect
this system for you, give their appraisal?>
There were not any holes drilled (something I will want to do, since my
preference is to have nothing showing, externally, e.g. pumps, filters,
intake outtake tubes, etc..), and the seller states there are some very
minor scratching on the top and bottom of the tank. He has not
mentioned any pits, or crazing, if that is true, from the research
I've done on acrylic tanks, seems like it is a pretty safe bet it
won't have any leaks. Am I correct in the assumption that as long
as it has not been abused, and was designed correctly it should not
leak regardless of age ?
The dimensions are 5 feet diameter, with 24" high viewing panes.
From this information, is there a thickness of acrylic or support
design I should be looking for that would show it was designed
correctly to prevent bowing issues?
<Mmm, 3/8" minimum... thicker would be better; not
The tank was constructed by a professional aquarium and parts supplier,
so I am hoping bowing issues were taken into account when it was made,
but it was constructed almost 10 years ago...don't know the history
of acrylic aquariums, has there been any acrylic tank design flaws
corrected in the last decade, that maybe I should be looking for?
Any help is greatly appreciated. Thanks, John
<Mmmm, If this is an "expensive" investment, I'd get
professional help (perhaps a good LFS employee) for assessment on site.
Re: how to inspect a used acrylic tank
I went to look at it today, and it did in fact have some what the
seller termed spider cracks in the acrylic. Very small areas of
deformities....they look like what has been described as crazing in
some of the other FAQs on your site. The scratching was pretty minimal,
he had an acrylic sanding kit (multi grade pads for a buffer)
<Mmm, be VERY careful here>
that he said would take the scratches out, and the acrylic used was
1/2". It could probably be a very nice piece with some work, but
think I am going to pass, for what the seller is asking, would want
something that needed less work. Thank You for the fast response.
<Welcome John. BobF>
Acrylic Scratches -- 01/11/10
Dear WWM Crew:
I first would like to thank you for the time and dedication you
take in answering our questions, it is much appreciated.
<<You are quite welcome>>
That being said I come to you for advice, I recently bought a 120
Gal aquarium for cheaps, nice looking nice price but filled with
<<I see them>>
It's not regular scratches, I am talking about clouds of
scratches, it's the kind of scratches you get when sanding
acrylic with the wrong sand paper.
So I make myself to investigate on how to repair this sucker, I
found info on another website about a guy who was able to remove
them scratches with 800, 1500, 2000 sand paper and a plastic
<<Scratch removal from an acrylic tank generally requires
more stages of "wet" sanding with much finer grits than
this, before the final polish>>
So I decided to give it a go, bought the sand paper (the kind you
use in car painting)
<<Can be utilized -- though I much prefer
'Micromesh' for this>>
and a plastic polish (PlastX).
<<The 'Novus' line of plastic polish is a better
choice, in my opinion>>
I picked one side of the aquarium that wasn't that bad as a
test side, it was the one with the least scratches and what I
thought would be the easy side. After a couple of days of sanding
and sanding and sanding on that side of the aquarium I noticed no
change at all, the only change I have noticed is that it's
now more scratched and the polish won't take that away.
<<The "polish" won't remove scratches -- at
least not until they are so fine as to be nearly undetectable/no
more than a slight haze. All scratch removal needs to be
accomplished by utilizing finer grits of sandpaper in
As my last resort I bought the Micromesh sand paper and the Novus
plastic polish kit,
<<Ah! A move in the right direction>>
and I'm waiting for the delivery. But the thing I wonder is,
in your opinion is this aquarium beyond salvation?
<<Not at all'¦ Even quite severely scratched
acrylic tanks can be salvaged, though this sometimes requires the
use of power tools and a skilled/experienced touch. It's hard
to truly determine the severity of the blemishes from the photos
but give the Micromesh and Novus products a try (follow
directions closely), you will likely be surprised with the
or can I make it look decent (don't want perfection just
<<Do also keep in mind that many of the lightest scratches
will "disappear" when water is added to the
I attach some pics of the aquarium in question for you to
analyze. Again I thank you for your time
and I excuse myself for my grammar, English is my not my native
<<Your English is fine, mate'¦ Cheers,
Buying a used 180g Clarity Plus Aquarium - Advice
<Hiya - Darrel here>
I came across a deal for a 180gallon Clarity Plus used aquarium, $1200
for the stand, tank, hood, 4 VHO lights, overflows, sump, pumps, UV,
etc. It was used for 5 years, and has been recently broken down. I plan
to store the tank until I have a space big enough to set it up in as a
My questions for you:
<If I'd known there was going to be a test I'd have studied
1) What are the typical expected life of an acrylic tank,
<There isn't exactly a service life for acrylic material, Doug.
Away from UV (sunlight) the material is stable and inert. There are
public aquariums that have had acrylic viewing panels for decades with
no deterioration other than the normal scratches and crazing>
<What's really at issue is how much STRESS has been placed on
the tank. Moving, leveling, water loads, etc. You can have seam
separation on a 3 month old tank if handled incorrectly.>
-- and what is the reputation of Clarity Plus?
<Clarity is owned and operated by the same people that make Sea
Clear which has been around for many years.>
2) Any tips for transport and are there any considerations for storing
the unit other than empty, out of direct sunlight?.
<Yes. The you haven't mentioned if we're talking months or
years, but the main problems will be the natural deterioration of the
peripheral products - the lights should be dismantled and the sockets
cleaned of any corrosion. Make sure they are BONE dry and then wrap
them in cellophane to keep them air tight.>
<usually the flexible tubing is a total loss because they harden
"in place" over time and the ends never fit snuggly when
reattached, so plan on replacing them when you do set up. That said,
you might keep them anyway because they old ones holding their shape is
a great way to know how to assemble everything when that day
<Make sure your sumps, overflows, UV sterilizer, etc. are all well,
Well, WELL rinsed in fresh water (tap water will do) and allowed to dry
completely. Everything that is submersible should be soaked in fresh
water - with as much as one cup of chlorine bleach per 5 gallons for an
hour, then soaked overnight in plain tap water. Then (again) allowed to
be bone dry before storage>
<IMPORTANT: If you have Mag-drive pumps and you plan to store for
more than a few months, disassemble them and remove the impellers!
Sitting idle inside the iron core causes them to lose their magnetism
and then you have to buy new>
<As far as the tank itself, the cleaning is equally important but a
little more problematic. You can't really SCRUB an acrylic tank,
but you really want to remove any mineral deposits and water spots
before putting it safely into storage (more on that at the end)>
3) The tank has some hairline scratches and crazing at the joints
(front-to-side panels) which I read in a plast blog was to be expected;
other than that it looks to be in good condition.
Before I store it and again before setting up I plan to water test it
<I wouldn't test it BEFORE storage '¦ except to the
extent of the cleaning and rinsing - and here's why: Filling an
aquarium puts a great deal of stress on it. It's designed for it,
of course, but it's still stress. Moving and handling a tank during
the purchasing, the transporting, cleaning and storage are additional
and different kids of stress. Setting up and leveling the stand,
placing the tank, verifying that everything is 'just right'
prior to filling the tank -- only to turn around and drain it is adding
stress that will only -- at the very BEST -- tell you nothing important
when you go to set it up & test again months later.>
Would you recommend reinforcing the joints prior to set up even if it
doesn't leak given the crazing?
<You can if you want to and some would say it can't HURT
'¦ but you asked if I'd recommend it and I say no.>
How would I go about this - just reapply weld-on over the existing
joints or actually weld-on square rod at each of the internal joints
(bottoms, sides, top)? What size square-rod would you recommend (though
I'd probably do this through a reputable shop).
<It's really an art form. Placing the material "just
right" so that the bonding agent flows EVENLY via capillary action
is something that usually takes many, many attempts before it's
mastered. If you do it wrong, the seams, the bubbles and voids show up
like sore thumbs. If you really want to, see if you can't get the
plastic store to do it for you.>
Thanks for the help - I am excited about the tank but have nightmares
reading the stories of seam failures.
<Welcome to our world. When it's time to set it up, make sure
that the test setup is perfectly flat and level before making your
"test" fill and then take great care in it's final move
and placement and you'll be fine>
Advice on crazing
I have had a 55g (long) TruVu acrylic for about 2 years. I
purchased it new.
<Mmm... darn cheap/er acrylic...>
About a year after I purchased it (a year ago) I noticed some
crazing had formed on front of the tank. Basically in a line from
top to bottom, slightly left of center.
<I see this in your pix... and take it this tank is set on a
planar, level surface... that this crazing is not due to uneven
There's one spot that's pretty severe near the bottom. I
wouldn't be too worried if it weren't for that spot,
sort of a cross-hatch pattern that I'm not .
See attached pictures.
I didn't worry at first (although I was disappointed that
this would happen in a nearly-new tank). However, now I can
actually feel the scratches if I run my fingernail across them on
the inside of the tank. I actually can't feel the really bad
spot, but I can feel some of the smaller lines above it.
Visually, however, the crazing has not gotten worse since it
first formed a year ago.
What is the potential for failure here?
<Smallish, but still... bothersome. T'were it me/mine,
I'd contact the folks at Tru-Vu... are they still in/near
Hayward?... and ask re replacement. Bob Fenner>
|Re: Advice on crazing
Thanks Bob. Yeah they're still around, I emailed them already
but wanted an objective opinion. -Dave
<Ahh! Our businesses sold many TruVu/Aquaplex tanks over the
years... in our retail stores, as set-ups and custom jobs... I
think one of the old owner (Bill's) son now runs this business.
They are not the only ones to suffer from the aforementioned
"less expensive acrylic sheet" blues.
Cheers, Bob Fenner>
acrylic repair. Houston, we have scratches
Hi I'm looking for some one to repair several scratches from our
They must be very reputable company to polish these tanks for the bass
pro shop. We have several huge aquariums in the Houston area.
<Mmm, give the brothers Senske a call at Aquarium Design Group:
If they can't do the job, they'll know where to refer you. Bob
Re: Larger Sized Aquarium (96x30x30) -- Glass or Acrylic? --
Thanks for the quick feedback.
In regards to your tank, (in particular) have you had problems with
scratching (hazing/crazing) - either the interior or exterior?
This is obviously the other fear with acrylic
<<Indeed'¦ This is one aspect of acrylic tanks that
needs to be kept in mind any time you do any maintenance in or around
the tank. Crazing is normal and usually doesn't cause any problems
if the tank was assembled/manufactured correctly (e.g. -- a
sufficiently wide radius used when cutting corners for openings in the
top panel). You're still going to get some amount of crazing here
and at the joints, but in my observations and experience, this has not
proven to be problematic. Scratching is a more serious
concern'¦ EVERYTHING can/will scratch an acrylic
tank'¦this does include your livestock. I've had Urchins
mar the acrylic while munching on the Coralline I let grow in the
corners for too long (this too mars the acrylic), and I have a Powder
Blue Tang that slap at its' reflection in the panels as the lights
go out, leaving tiny marks with its 'scalpels.' But these are
miniscule compared to the greatest danger to an acrylic
tank'¦THE AQUARIST! You will do far more incidental damage
than any other organism'¦and ironically, mostly while
'cleaning' the viewing panels. But fear not, this is not as
dire as some may think. Most 'marks' left on the panels are
insignificant (though they don't 'look' that way), and
while unsightly, they can usually be easily rectified. There's a
wonderful product called 'Micro-Mesh' that every acrylic
aquarium owner should have in their arsenal. This micro-crystalline
abrasive can be used 'underwater' without harm to your
tank's inhabitants, and there are even 'magnet kits' for
use with your Algae-Free or Magnavore cleaning magnet. It's not
cheap, but I find keeping a fine pad of Micro-Mesh on my cleaning
magnet at all times not only speeds up the chore, but also keeps those
unsightly scratches at bay>>
...although I presently have an acrylic sump that I abuse, and there
are NO signs of hazing/crazing/deep scratches.
<<As stated, scratching is a problem'¦though not as much
as most think with a little careful thought given re. I will warn
though, stay on top of those Coralline deposits. It is difficult to
remove (best done with a heavy-duty scraper 'made of acrylic,'
not plastic'¦can be DIY'd) and etches the acrylic, getting
worse the longer it is left alone>>
Also, any signs of your tank bowing along the front panel?
<<None'¦ But this is due to the quality
Â¾' acrylic Tenecor used, as well as the robust support
web of the top panel (also Â¾'). Pay the extra dosh to go
with an established and reputable manufacturer>>
Help? Is Acrylic Aquarium Repair okay?
Have a question. We currently have a 500 gallon acrylic fish tank
(my husbands baby) that had a miss hap. Long story short I
thought it would be a good idea to have Dish Network come out and
put satellite in our home.
Well the guy that came out to install missed our outside wall by
over a foot and drilled into our garage right into our 500 gallon
acrylic fish tank.
<Oh, check before you drill, just as digging!>
Thank god it was not full but the issue is! Dish wants to just
patch the whole that is more than half way through the tank. They
say they have someone that could do it. I just need some input on
this or something that would help back us up.
<It can be done, but I would urge you to get opinions of your
own local acrylic workers, not whoever Dish recommends.>
The tank is about 10 feet long 4 1/2 feet tall and about 3 feet
wide. The acrylic is 1 inch think. The whole that this guy put in
it is like I said more than half way into the tank. It also has a
cut right below it were the other part of the drill bit started
to go about. The whole is about 1 foot from the bottom and about
1 inch from the seem on the side of the tank. (3 feet wide
<If this tank is indeed 4.5 feet tall with 1" acrylic
this alone is a concern.><<Yes, bow-city.
Thoughts? Suggestions? Is it possible to patch this with out it
blowing out in the future?
Anything on water pressure and patch jobs?
<A good job done here will actually "weld" new
acrylic into the holes, though there will likely be some visual
distortion at this spot. Again I urge you to get estimates from
your own local experts. I have learned not to trust this
particular company through the years. This could be done
yourself, though with their liability I would have an expert do
Thanks in advance (Photos attached)
Jackie (Mrs. Halfcrimson)
<Welcome, Scott V.>
cut from outside end panel... and side view showing pilot and
beginning of rim cut from outside, right
Re: Help? Is Acrylic Aquarium Repair okay?
Please see below for questions in blue..... Thank You!
<Very welcome, I have collected your follow-up below for ease
Sorry about not having the exact; just trying to help the husband
figure this out. But he said its about 4' tall 8' or
10' feet long and 32 inches deep. Not sure if that helps but
why would the 4.5 feet tall with 1" be a concern?
<Ah, 32" deep/tall makes more sense! As an aquarium gets
taller the acrylic needs to be thicker to counteract bowing and
possible failure due to the increased pressure created by the
vertical water column.>
That's what I was thinking. Besides talking to locally
acrylic people is there a place or suggestion on how to research
pressure in tanks and so forth?
<Nothing off hand. Online tank calculators such as those found
at GARF.org can give you a general idea of how thick acrylic
should be for a given height, but there is not anything out there
I know of that will help you calculate the potential for failure
in your situation. This tank is can be reliably repaired, my
caution comes from the standpoint of not just trusting any Joe
Blow that they send out.>
Will defiantly check with an expert here and thanks again for the
thoughts and ideas....
<Welcome, Scott V.>
Acrylic Aquarium Crazing Repair (And Bulkhead Installation)
I have recently purchased a used 120 gallon Sea Clear acrylic aquarium
24 inches tall, 60 long and 18 deep constructed of 3/8 inch panels.
<<Mmm, be aware you may experience some slight bowing of these
panels at this tank height. Nothing that should cause any problems
structurally, but Â½' material would have been better
After taking it apart for transport and then reattaching the bulkheads
(which are on the bottom of the tank) it was leaking at the seals of
the bulkheads. So I then replaced all the rubber seals and it still
leaked. Well then I used a wrench to tighten the bulk heads and I
plugged the bulkheads that were leaking. One of the bulkheads was still
leaking and to make matters worse it looks like I over tightened the
bulkheads and now I can see crazing radiating out from the bulkheads
about 2 inches.
<<Yep'¦too much 'oomph' with the
I cannot feel any of the cracks from the surface and they appear to be
within the acrylic panel. If you look at it from the side you can see
the crazing is just below the inferior and superior surface of the
panel and is less than 1/16 of an inch. So can this tank be fixed and
any tips on getting bulk heads sealed?
<<I think so'¦and yes>>
I read through your website and was thinking that maybe using Weld-on
and putting an acrylic patch over the crazed areas may be good
<<Is one option'¦ Make the patches about 2' larger
than the crazing, and use material of the same thickness as the bottom
panel. A better option would be to fit and solvent weld a whole new
bottom panel atop the existing bottom panel. Make sure you clean up the
bottom interior and apply any patches from the 'inside' only,
as acrylic tanks require support along the entire surface of the bottom
of the tank and any patches applied to the exterior will obviously be a
problem re. Whichever method you use, I suggest you drill new
throughputs in a different location and don't try to reuse the
existing compromised holes. You might also want to consider moving the
location of the bulkheads from the bottom to a side or back panel. As
for 'seating' the bulkheads themselves'¦ First, I
place the washer so it will be on the wet-side of the bulkhead, then I
run a heavy bead of silicone sealant around the edge of the hole on the
outside. Insert the bulkhead from within and hand-tighten the nut on
the outside then give it about a quarter turn with a wrench to snug it
up. Let the silicone cure before adding water to the system (overnight
or longer) and you shouldn't have any problems with 'leaky
bulkheads.' The silicone forms a flexible yet solid seal that is
still easy enough to break free should you ever need to remove the
However this tank was cheap and I really don't want 120 gallons of
water on my floor.
Thanks for your time and you have a great web site, Jake
<<Happy to share'¦ Eric Russell>>
Re: Acrylic Aquarium Crazing Repair (And Bulkhead
Installation) -- 06/11/10
Thanks again, I really appreciate your help, Jake
<<Quite welcome... EricR>>
Acrylic tank repair help, holes, crazing
Dear Crew at WWM,
<Hiya - Darrel here>
I recently obtained a 135 gallon acrylic tank. It is in decent
condition and all seams look intact. The only problem I have is that
the previous owners drilled two small holes (maybe 1/8" in
diameter if that) in the front of the tank about 2 inches from the top
and I would like to fill the tank beyond the holes.
<In the FRONT of the tank? Hmmm. Strange, huh?>
I know I could cover the holes using a solvent and another piece of
acrylic but because the holes are in the front and this could be a
Do I have other options?
Could the holes be "plugged" using a thicker/viscous
<Not really. All solvents used to bond acrylic are designed to bond
two pieces together. What I gather you have in your mind would be to
fill the holes with something like silicone sealant *IF* you could find
some that would dry perfectly clear, right? The answer to THAT is
"no, unless you don't mind the glue failing and leaking water
<The cure for this depends on how artistic you are. You could plug
holes THAT small with silicone, but then, instead of a hole, you'll
have a very small wad of "almost clear" filler.>
<You could find a plastics store and buy a length of clear rod just
a tad bigger than the existing holes, then drill the holes to a few
hundredths of an inch larger than the rod, cut a length as thick as the
face of the tank, insert it in and THEN place solvent around the edges
and let capillary action draw it in -- the plastics store can show you
how to do that.>
<Go to a home center store and get some nylon bolts and nuts of the
appropriate size and two plastic coat hangers like you put on the back
of bathroom doors. Coat the bolts and nuts with silicone and install
the bolt through the coat hanger and then through the front face and
screw the nut on from inside. Now you'll have two coat hangers on
the front of your tank that will completely EXPLAIN the two holes ...
if not actually take people's attention from them. Now every once
in a while someone WILL ask>
<Hey Arnel!! Why do you have coat hangers on the outside of your
<And you can look at them, roll your eyes and say "because when
I put them on the INSIDE of the tank, our coats got all wet!!! Sheeesh,
what is WRONG with you ????>
<Or in the same bins where you'll find the nylon bolts, they
have Rosettes -- round clear plastic buttons used for mounting mirrors.
Same deal as the coat hangers -- sometimes we draw ATTENTION to things
we're trying to hide, but if we actually USE them, they merely look
<I have a bunch of other suggestions for how to use those holes, but
I'd better get off this computer before they trace the
Also, there appears to be what look like scratches within the plastic
(not on the surface). I have had tanks have these and not have any
problems with leaking but can anything be done to remove these
<The term is 'crazing' and it's just what it appears -
minor cracks right in the material of the acrylic. Unfortunately,
there's not much that can be done about it.>
Thanks and any help would be greatly appreciated.
Acrylic tank pit repair -- 03/19/10
Hi, I have a 125 gallon Acrylic tank I recently purchased. It is
1/2" Acrylic. There is a pit in the front about 3/32" deep
and about 3/4" wide and 3" tall. The previous owner claimed
it happened from solvent fumes getting too close to the tank. It is
deepest in the center and feathers out to flush on the edges.
Supposedly the original owner
claimed you could fill the pit with Weldon #16, let it dry and sand and
buff it out and would have a clear repair. Is this possible, likely,
<Not likely a good repair... Most folks opt for "grinding
down" the area around such imperfections, but this can add a good
deal of visual distortion... Is the back clear? If so, I'd just
"turn the tank around"... even if this means losing a
"rounded corner" or two. Otherwise, maybe a few emails to
acrylic fabricators will reveal a better fix. Oh, and I would also NOT
try fire-brushing this pit away. Bob Fenner>
Re: Acrylic tank pit repair
Thanks Bob. There is a fabricator in town that says he can do it. I
guess I will take it to him. He has a pretty good reputation.
<Ah, great. Please do send along some before and after pix. Cheers,
Worried about new (used) acrylic tank. --
Just bought a 75 gallon tank last weekend. It was filled when I
got it and haven't had any leaks however I noticed the joints
look strange like little cracks in places wanted to know what you
thanks so much
Oh Attached some pics of it
<Is "crazing"... small fractures in the acrylic due
to stress. The extent doesn't look too bad here... I
wouldn't be overly-concerned in other words, re the potential
for failure. Read here re:
Acrylic Tank question... haze source 19.01.09
I have a question in regards to my Acrylic Tank. I have a severe
visibility problem. It is hard to describe or take a picture of. The
majority of my tank has what looks to be a haze than can't be
removed by any type of traditional scrubber.
If looked at closely, it seems as if the surface has been etched. Looks
like the meandering trails of snails in some areas, where as other
sections look to be something else. I searched your postings on the
topic of snails and whether they would be able to scratch an Acrylic
Tank. The answer seems to suggest not.
I have Turbos and Astrea snails which I have had in my previous tanks
with no problems. This particular tank is the first one that I have had
any problems like this. I do have a bunch of little 1/2" Chitons,
but I didn't read anything about them doing any harm.
<These can scratch acrylic with their radula, but again, are almost
always on rock, not aquarium sides>
The only other culprit is a cowry, either a Money Cowry or possibly a
Serpent's Head Cowry.
<Ahh, Cypraea caputserpentis... a fave Hawaiian animal.>
It is about an 1.5", so not real big. Could he be doing this?
<Not a whole panel, no>
Besides the critters, there was a time when I had quite a bit of
coralline algae on the walls. Upon scraping it off, it would leave a
bit of a haze behind, as if it had eaten away at the acrylic.
<Mmm, maybe... best by far to buy/use a specialty scraper, or credit
But whether it was the algae or some sort of creature chewing on the
algae, I couldn't say. Any ideas?
<May be time to drain, buff this tank's insides...>
At this point I have purchased an acrylic scratch remover made up of a
bunch of different grits of sand paper.
<Be careful with this last... more damage than its worth here.
Better by far to use the liquid/pastes and a small (hand size) power
tool/sander with a buffing pad>
Lot of work, but it does seem to remove this haziness without having to
drain the tank. I think I am going to have to do it anyway to reach all
the areas though. I am just wondering if I need to remove any of the
aforementioned critters to be safe, besides removing any algae the
minute I see it begin to form.
Thanks for you time
<Please read here: http://wetwebmedia.com/acraqscratch.htm
Buffing An Acrylic Tank -- 08/26/09
I have purchased a used 300 gal acrylic tank and while removing the old
paint from the canopy some of the stripper used to remove the paint
dripped on to the side of the tank.
<<Mmm'¦left some nasty marks no doubt>>
Now there are two lines where the chemical ran down the tank.
<<Indeed'¦ It really doesn't take much to mark up an
What would you recommend using to remove these lines?
<<There are various methods and products about. One of the best
solutions is the product line from Novus. These are liquid polishes in
various 'grits' that you use in succession and can remove
anything from heavy scratches and abrasions to light haze. Another good
option is a product called Micro Mesh. This product is more like
traditional sandpaper but comes in very small grit/mesh sizes for
buffing out abrasions in acrylic/plastic. Try a keyword searches on the
names and see which you think suits you best>>
<<Happy to share'¦ EricR>>
RE: Buffing An Acrylic Tank - 08/27/09
Thank you for your help! I will definitely check these out.
<<Quite welcome... EricR>>
acrylic woes. Nah 5/10/09
I have a Clear for Life 55g acrylic show tank that I've had
set up for around 3 years now. I chose acrylic because it looks
nice, I liked the rounded corners (at first...I don't like
cleaning them though...), and they are supposedly bomb proof
since they are less ridged and don't have the risk of failing
at the silicone seams.
my biggest concern was scratches, crazing and cracking. Scratches
and crazing? ok...herding cats, I'm over it, but cracking was
still a huge concern, so the stand is on carpet (I have wood
floors) to help level and absorb any imperfections in the floor,
and the tank itself is placed on 1/4" Styrofoam sheet (as
per just about everyone's suggestions) to help level the tank
and so on.
anyhow, I'm moving in a week and completely restarting my
tank. its been broken down, livestock sold, etc, mostly I wanted
to start something new besides the usual community reef (I
don't now what yet). getting to the point, when sitting down
to start some scratch repair, I noticed some crazing around the
rounded corners of my tank towards the top. I'm my reading
(on your site, on scratch repair) it said watch for parallel
cracks, particularly around the bent corners as they might be of
<Parallel AND interconnecting verticals may be...>
I've attached pictures of each side, they run parallel to the
floor, the right side seems to be worse than the left. Should
these cracks be cause for panic?
fortunately as I said there is no water in the tank but I'm a
little concerned to even think about refilling it since I read
these cracks could mean impending doom.
<Naught to worry about here Mike. These are akin to
"stretch marks"... the material weakened during heat
bending/fabrication... not a cause for feelings of dire doom.
This tank will not fail. Bob Fenner>
Crazing in my new/used 180 gallon tank.
I am pretty sure I have made a terrible mistake buying my first
I am in need of serious help. I purchased a used 180 gallon
"Sea Clear Aquariums" fish tank.
<Am very familiar with the company (and its subsidiaries,
other businesses) and its products>
After reading your wonderful site, I believe it is
"crazing" in the front middle and around few
edges/corners of the tank.
<Mmm, the one pic looks like repetitive impacting (maybe from
a hood?) the other appears to be crazing...>
This tank is only 3/8" thick all around, which I now
realized it is much, much too thin for a 6'x2'x2'
<Mmm, yes... and "is" thick "enough" for
these dimensions... though, if it were me, I'd make these out
of 1/2"... Do badly bow in the mid-back and front...>
I was advised by an Expert that I can't fix the crazing but I
can prevent it from getting worst. I need to know from you if
this is sound advise- I will need to reinforced the top panel of
the tank (between the two openings) with three 3/4" or
1" thick pieces of clear cell cast acrylic.
(2)6"x24" and (1)23"x24" using Weldon
<What? No... this won't help here>
The materials for this reinforcement will be around $100. Will
<It will indeed! IF you can find, buy acrylic for this cheap,
get all you can, sell it at market and buy yourself a new
I spend a lot of money on this tank and do not want to spend more
if I can fix it.
<I would spend nothing on the present tank for a repair... it
won't likely "fail"... catastrophically...>
The tank is currently sitting empty in my garage. Please
I have attached pictures. Thank you in advanced.
<How to state this better for you? Many acrylic tanks have
such imperfections... some getting worse quicker... Tanks et al.
are fabricated of thinner materials to "keep costs
down"... What you have is not atypical. Bob Fenner>
Re: Crazing in my new/used 180 gallon tank
Thank you so much for the respond. I just want to clarify a few
1. Are you saying that by reinforcing the top panel with
additional 3/4" thick acrylic will help prevent further
"crazing"? This will help, not hurt the tank.
<It will make no difference re the crazing.>
2. Will 1" thick be better?
3. Will the additional weight (from the new three pieces) on top
of the tank "harm" the tank?
4. Is it your advice that I do not need to "fix" this
problem, but if I want to (for my peace of mind), it will help
the " longevity" of my tank?
The cell cast acrylic I am buying is from Ebay.
<I would not use this....there are some very inferior acrylics
out there even though they are cast.>
<Welcome, for what it is worth I would just use the tank as
is...as Bob said it will bow quite a bit, that is the M.O. of
this particular model tank. Save your money for a future tank!
|Acrylic Seam Cracks/Crazing 7/3/08
Greetings, <Larry.> I enjoy reading WetWebMedia on a regular
basis. Thank you very much for all the time you put into this site!
<Ahh, thank you!> I have a Clarity Plus 240 gallon acrylic
aquarium (8x2x2) that I recently purchased. The previous owner used
it right up until I took ownership of it. They just moved to a new
home and have a 300 gallon reef built into one wall. <Fortunate
for them, and you!> The tank looks to be in perfect condition
except for the seam where the top of the tank meets the front of
the tank. All other seams are crystal clear and look absolutely
perfect. There are tiny cracks in the seam itself. I have attached
a photograph showing what it looks like where the cracks are the
worst. <Appears to be normal acrylic crazing. This can form due
to manufacturing, stress, heat, acrylic used and about a million
other reasons. Not really of any concern so long as they do not
extend past the seam.> I would say that there are no cracks
along half of the seam, minor cracks for the other 30% of the seam
and the type of cracks as seen in the photograph for the remaining
20% of the seam. How much should I worry about this joint? <No,
just about every acrylic tank has this to some extent in time.
Given the location and lack of crazing in other areas it was likely
caused by weight from a canopy/lighting fixture.> I read on your
site that someone was planning to gusset the inside of a seam with
square acrylic rod and some Weld-On. The canopy for this tank
overlaps the top of the tank by about 1-1/2" so I have some
space to work with. Do you think that if I purchased some 1/2"
or 3/4" square or triangular rod and used some Weld-On that
would strengthen this seam substantially to take any worry away?
<You certainly could do this if it makes you feel more secure, I
honestly would not go to the trouble here.> What shape and size
of rod and which type of Weld-On do you recommend? <A little
will go a long way. Your tank is likely Â½', so if
you were to use Â¼' rod you have increased the
seam-weld area by 50%. It will cost you little to nothing to pick
up a piece of Â¼' scrape from a local plastic
fabricator, you can cut some strips. Weld-On 3 or 4 will work
fine.> Thank you for your time!
<Welcome, Scott V.>
Question on sanding out acrylic scratches in an aquarium
5/1/08 Dear WWM Crew, <Ave!> First, I want to thank you
for the wealth of information on this topic already available on
your website. (see the following link
http://www.wetwebmedia.com/acraqscratch.htm for my previous
attempt to answer the following question). <Okay> I am
excited to say that I bought a beautiful 180 gallon acrylic tank
(see attached pictures) and am in the process of setting it up.
Unfortunately, I created quite a few scratches when I used a
certain unnamed pad (looks like many others have done the same).
<Argghhh!> Now I am trying to fix the scratches I made, but
I am somewhat crash-strapped. <Heee! Like those car test
dummies?> I noticed that the micromesh sandpaper sets (~$20 x
# of packages I need to fix all my scratches .... E.g.,
are a lot cheaper than buying a complete acrylic aquarium repair
kit (~$100), but I am afraid that, given your karate kid analogy
made earlier (see WWM link above), I am signing myself up to more
pain, sweat, and effort if I try to use micromesh types of
sandpaper than just using Novus-like products. Here are my tools
I have available: (1) Powerful 1/2 inch drill, (1) Orbital Sander
(1) My hands. <Good ones... the drill will likely be too heavy
to use here> Here are my questions: What tends to make for the
least work in repairing lots of light and a few deep scratches?
1. Use the micromesh or acrylic kits 2. With or without
associated liquids (see Novus examples on the following link:
) with the drill or orbital sander attachment (at low speeds to
avoid overheating the acrylic) in your experience? <The
latter, number 2> 3. Can I get by without the liquids, keep
the power tools and micromesh? I have a bottle of Novus 2. Should
I get more, as well as Novus 1 and 3? <I would get the other
numbers/grades... as you'll see, they are necessary...
you're in actuality grinding down the surface... need to make
all scratching the same depth...> 4. What tends to make the
most sense to get the most professional looking results ..... I
think your answer to this one on the WWM link was
"nothing", but I thought I would ask since my question
was a little more specific than the others. Help....... Alex
<You will be able to most definitively answer yourself...
You/I might try/experiment with the micro-mesh material... but if
it were me, mine, I'd "buff" out all with the Novus
polish or equivalent, and the orbital sander with soft pads...
Bob Fenner, been there, done this...>
Re: Question on sanding out acrylic scratches in an
aquarium 5/1/08 Thanks. <Welcome my friend. Please do send
us a follow up... and a pic of your bigger arms! BobF> Re:
Question on sanding out acrylic scratches in an aquarium
5/1/08 Will do, and thanks again. I plan to possibly start
tomorrow, and work thru it off and on this weekend. <Ahh, put
on some good music...> I am sure I am pipe dreaming by hoping
to complete one pane this weekend. But once it's completed,
I'll be sure to send you a picture. Thanks again, Alex <Is
actually not that big a job... given the "right tools"
and frame of mind... I've had some HUGE scratches there were
a pain... these minor ones will rub out... now, the edges... will
take a bit more finesse. Cheers! BobF>
Used 150 gallon Truvu acrylic aquarium
04/14/2008 Hi there, I recently purchased a used 150 gallon
Truvu acrylic aquarium (72x24x20) that came with the stand and
lighting for 500.00.I drove several hours to get it and
didn't notice anything wrong with it till I cleaned it and
noticed these lines along the seams. It's along most all the
seams. My husband thinks I'm overreacting but I don't
want to find 150 gallons of water in my living room. It does get
complete bottom support with the stand. I have enclosed a
picture. Is this bad? The tank is up and running and doesn't
leak. Do I need to worry and replace the tank? Thanks for you
time Angie Smith <This degree of "crazing",
stress-cracking age is not problematical. You shouldn't have
problems here. Cheers, Bob Fenner>
Re: Used 150 gallon Truvu acrylic aquarium -
04/14/08 Thank you for your reply, just to double check,
these cracks are along pretty much all the seams and they will
not contribute to failure? <Not substantially, no. Were they
much "deeper", penetrating to the "water
side" this might be so... but as it is, this tank has many
more years of good service> Sorry if I seem to be a pest just
don't want to spring a leak. Thank you <I do understand.
Re: Used 150 gallon Truvu acrylic aquarium, CF
lighting above. - 04/14/08 One more quick question, would it
be ok to have my compact fluorescent over the top of the tank and
the Eurobracing or do I need to invest in lights that go over the
two holes on the top of the tank only? Thanks again, Angie <If
the lamps themselves are a good two-three or more inches above
the acrylic, and there is some circulation (passive even, from
just exhaust holes) you should be fine here. BobF>
Links 08/08/2005 Hi, I am a reefkeeper and regularly scan
your site for answers to questions. Very nice site, thank you. We
recently launched a company called Everclear Transparency Refurbishing
Inc (aka ETR-INC) at www.etr-inc.com We primarily sell acrylic scratch
removal kits and products right now, but are quickly expanding our
inventory to include other scratch removal accessories and maintenance
products. We also plan to add lots of useful information and tips to
help reefkeepers avoid scratches. Could you please post a link on your
site for us? <Will gladly do so> At some point we may be
interested in buying some ad space on your site but we're too poor
right now. Thanks again! Regards, Scott Everclear Transparency
Refurbishing Inc. www.etr-inc.com < http://www.etr-inc.com/> firstname.lastname@example.org <mailto:email@example.com> <Bob Fenner>
More Myths About Livestock Scratching Acrylic Tanks - 11/18/05 I
recently bought a 220gal Tenecor tank (72X24X24) with the Simplicity
Plus system with the intention of setting up a FOWLR system. I
originally wanted to buy a shark, but after reading your site, I
realized that this tank is simply too small for one. <<Yes, and
shaped wrong too.>> I would like to put a couple of triggers in
though, maybe a Blue Throat and a Picasso. <<Cool! I have a Blue
Throat in my Tenecor 375.>> The guy at my LFS said that triggers
sometimes scrape their teeth along the sides of the tank, and since
this is an acrylic tank, I thought I'd better check. I've never
read about this behavior, have you? <<Nope...probably falls in to
the same category as the stories about the Ctenochaetus genus of tangs
scratching acrylic tanks with their teeth...mostly wives tales.
>> <<Did you bring this up with your wife?
MH>> I think you need not worry...and believe me when I
say...YOU will put far more scratches in the tank than any
fish!>> Thanks! Robert in Texas <<Welcome, EricR in South
Carolina>>>Mmm, do agree with the hobbyists causing more
scratches... but have seen trigger-made scrapes in acrylic... and a
Pleco-destroyed one recently. RMF< What causes Acrylic crazing -
01/23/2006 Hello <Hi there> I have three questions that I
hope you can answer. 1. What causes crazing in acrylic? Does it
normally occur when the material is under tension or can it occur in
raw sheets of acrylic also? <Mmm, some acrylic seems to craze much
easier than others (one could say this is a "quality
difference" I suppose). And some does this without actual
construction, use, with time... particularly if/when exposed to
sunlight, heat... But most crazing does occur in actual practice, in
areas of higher torsional stress... corners, near upper front
seams...> 2. I have heard about a two part acrylic cement that some
acrylic aquarium manufacturers use, they say it produces stronger bonds
compared to standard the standard one part" Weld on" cements.
Can you tell me what this two part stuff is? <Nope, don't know
re> I've never heard of it. It sounds like a type of epoxy but I
don't know why one would want to use epoxy to join acrylic. <As
far as I'm aware, Weld-On and similar solvents actually melt the
acrylic together (not cement)... done "right" (square cuts,
clean...) there is nothing stronger as far as I'm aware> 3.
I'm planning a tank 120L X 24W x 30H using 1" cast acrylic for
all surfaces. I'm trying to keep bowing to a bare minimum for a
tank of this size, do you feel this height is safe for 1"
thickness? <Oh yes> Have been reading your site for awhile and
respect your suggestions, this site has been a great resource to many
of us. Thanks again. Sean <Thank you for your kind words,
acknowledgement. Bob Fenner>
Underwater Acrylic Scratch Repair -
06/29/06 Hello, <<Hi!>> I must have picked up a rock
cleaning the acrylic and got several scratches on my boss's 90
gallon tank. <<Is easy to do>> I ordered the product above
and would like your opinion on using it. <<Is fine for small
repairs>> Can you really use this product under water with the
fish in there? <<You can. The sanding action obviously will
liberate fine acrylic particles in the tank, but these are not harmful
to the tank inhabitants in my experience>> Do you know if it
works well? <<That depends much upon you. Follow the directions
closely taking your time, and don't "skip" grades of
abrasive. Also, be sure to "feather" the repair to reduce the
risk of creating a "lensing" effect. And if you find you need
more/finer abrasive sheets you can get them here without buying another
I understand it's time consuming but that is no problem.
<<Indeed...not an easy task>> Also we would like to buy a
clownfish but we're wondering which would be the less aggressive?
<<Mmm, in my opinion Amphiprion percula is one of the more
"gentle" clownfish species>> Thanks for your help!
Nancy <<Happy to assist, EricR>>
Acrylic Tank Scratch Repair - 06/07/06
Hello, <<Hello>> I found your site on Google and wonder if
you can help. <<I'll try>> A friend of mine recently
bought a used 300 gal. acrylic tank. <<Neat!>> The problem
is it's scratched from head to toe. <<Common>> We said
we would make it a project to restore it and have since bought a few of
the Pentair restore kits, but this seems to be making the problem
worse. Spoke to a representative from the pet store who informed me
that it is impossible to fix that size tank with the repair kits, it
would take forever. <<Indeed, these kits are meant for
touch-up/spot repair>> I have however seen where you recommend
Novus. <<A good product, yes>> Is it similar to the scratch
removal kits in that you have to sand the acrylic, or is it just a rub
on formula? <<Novus is a "liquid" with different grades
of abrasives used in succession. Best/quickest results come from using
in conjunction with a power buffer (electric or air), but can also be
used "by hand"...with much elbow grease>> How many
ounces would it take to complete a tank this size (8ft/3ft/2ft)?
<<Difficult to say, depends much on the degree of damage...but
likely cheaper in the long run than the Pentair kits>> Also, I
don't know if I am pressing too hard on the sandpaper, but I
can't seem to get out all the lines I have made. They are extremely
fine but still visible at an angle, and hazy in some spots. <<Are
you using the paper "wet"? Have you tried buffing with the
liquid polish? These kits are pretty good for small touch ups on a tank
that is "in operation" as you can use the abrasive sheets
under water. But given the fact that your tank is "dry", I
would proceed with the Novus product. You might also try posting your
questions/challenges in the DIY forum on Reef Central. There are
several acrylic tank manufacturers that frequently monitor the forums
that could likely provide some useful tips>> Your assistance
would be greatly appreciated. Much thanks, Issaco Mignott <<Good
luck with your project, Eric Russell>>
Scratch-Proofing an Acrylic Tank...Not Practical Really -
01/21/07 I have a 90 gallon acrylic tank (marine) that I'm
setting up which is starting out unscratched. I am planning to fill it
with a lot of live rock, which I'd like to allow to lean against
the back, and side walls of the tank, <<It's best to leave
space between the rock and the tank walls for adequate water flow to
preclude dead spot/buildup of detritus>> so I'd like to put a
thin layer of something inside the tank to protect the acrylic from
being scratched by the LR. <<Mmm...not very practical
really>> Ideally it would be black. <<Then what why worry
about it if you won't be viewing the tank through these panels?
Since I can't roll up a sheet of glass to fit it through the access
holes in the top of the tank, I'll need to use something that is
flexible enough to roll up and get inside. <<Then you will have
problems with the edges "curling" as gluing something in
place will be difficult and will also "mar" the
acrylic>> What can best meet these criteria (and please add any
criteria that I should also consider): 1) non-toxic 2) not very
expensive (less than $20 for a 2 x 4 foot piece?) 3) looks nice in the
tank (not a lot of seams) <<Nothing that comes to my mind will
fit these criteria for reasons I've already stated>> How
should I affix the material to the back wall? If I use an adhesive, it
must be removable later and not hurt the acrylic (or the fish).
<<Again, not practical...pretty much anything that would hold
will mark/etch the acrylic>> If I use silicone adhesive, will it
discolor or damage the acrylic? <<I have seen this cloud/discolor
acrylic>> Will it adhere well enough? <<As I see it, your
only options to black-out the tank back/sides is to either paint the
outside surfaces or affix painted panels to the outside
surfaces...neither of which will prevent scratches to the inside of
course>> If I just lean it in there, will I have problems with
live stock or algae getting back there? <<Likely so, yes.
Honestly mate, what you propose is just not practical in my opinion
with the small openings limiting the use of "rigid" material
and the adhesive "marking" issues. I think you'll just
have to bite-the-bullet and accept the fact the back/sides will get
scratched. As will the front, despite your best efforts...trust me I
know [grin]. On a positive note, if you decide to sell or use this tank
in a different configuration some day (e.g. viewed from two sides), the
scratches can be removed and the tank polished to look like
new...though not without a measure of "elbow grease">>
(I'm considering making this an octopus tank) <<Be sure to
read here ( http://www.wetwebmedia.com/cephalop.htm) and here (http://www.wetwebmedia.com/cephsysfaqs.htm) as well as among
the associated links in blue at the top of the page. Regards,
What eats acrylic? Dear Bob, A quick thank you for all
you've done for us 'salts' out there. I reference WWM
frequently and often and thank you and Lorenzo for all the time,
effort, and sage advice you've devoted to people's better
understanding of the life forms and biotopes they keep. <A pleasure
and honor my friend> I have a question regarding what I believe to
be radula marks etched into the surface of an acrylic tank. I recently
helped a friend break down his 40 gal. tank (SeaClear or TruVu, I'm
not sure which). He had (sadly) neglected any maintenance on the system
since his last specimen died some two years ago, only adding top off
water. Needless to say it was a huge mess, but somewhat of an
interesting study from a scientific perspective. As I began to scrape
of the thick filamentous algae covering all sides of the tank, I
noticed a haze on the front panel. Upon closer inspection, this haze
was a pattern of etchings in the acrylic surface! The pattern matches
that which I have seen snails (esp. turbo) leave as they graze through
a patch of Cyano. Is it possible for snail's radulas to be so hard
as to etch into the acrylic? <Yes... for browsers, many gastropod
mollusks have a rasping mechanism... a "tongue" called a
radula (important in its characteristic make up for species
identifications at times) that is constantly being regenerated in the
back of the mouth, worked by a muscular device, the odontophore... that
these various "snails" use to scrape away micro/macro algae
et al. from hard surfaces as food... Some have modifications, additions
of specialized salivas, bore into shells, melt rock...> I am
wondering if you have ever encountered this, and if so, what species of
snails you have associated it with. I am sure this info would be quite
interesting to everyone out there with an acrylic reef tank. <I have
seen this sort of marking... and simple "stress fracturing"
that looks similar... in acrylic tanks. Don't know which specific
species might be involved though. Bob Fenner> Sincere Thanks,
Is acrylic scratch remover safe for fish? Hello Mr. Fenner, I
just got finished putting my new tank together. I have the powerheads,
the heater, and the aragonite sand and water in. I have not yet put it
the salt. I'm just testing the components and letting the sand dust
settle. While inspecting my tank, I noticed in the light that there
seems to be a very slight haze in a couple upper corners of the tank. I
believe it might be from the TruVu SRK (scratch remover kit). <This
may be so... or typical "stress fracturing" marks from
heat-bending in those areas> I might of accidentally not rubbed off
all of the scratch remover paste thingy. The water has a oil spill type
look when viewed at a lower angle. Is this bad? Shall I take out the
water and wash the tank again? Please help. Thank You. <Ahh, our
businesses (retail and service) used to sell many TruVu/Aquaplex
tanks... and I've spent many hours with the green and tan pastes
you mention in their scratch removal kit. This material is not toxic. I
would not take the tank down, or worry. Bob Fenner> Stan
Taking out scratches from the inside Bob, do you know of any
acrylic scratch removal kit that works underwater? <No... all
require draining the system at least down to the level of the work. Bob
Fenner> Thanks, Lee
Re: Is acrylic scratch remover safe for fish? Thank you very
much. That is what some people suggested on ReefCentral, but to hear it
from an expert like you makes me feel so much better. Thank you again
and have a Happy New Year. Stan <You as well my friend. Be chatting.
Crazed Acrylic/Tank Cleaning 4/12/07 Hi Crew, <Hello
Christine> I was wondering if there was any way to fix crazed
acrylic in an aquarium? Is it just buffering it out, or do you have to
just replace the acrylic (which would be hard considering I'm
talking about a seamless tank)? I'm asking because I am considering
buying a 100 gallon tank, but it is crazed in the center of it- almost
1 ft across and almost the entire height. I have no knowledge how it
happened, <May not be crazed, but scratched from cleaning with
abrasive material. Generally, this won't be quite as noticeable
with water in the tank. My advice would be to buffer the acrylic with
an acrylic cleaning kit such as Lifeguard's. This will remove
scratches, but if it is crazing, it won't help much. Drs. Foster
& Smith sells this product for around $20.00.> do you know any
reasons why acrylic crazes? <Generally from stress and/or cheap
acrylic which is more brittle than quality acrylic geared for aquarium
use.> Thanks for your help, your website is terrific! <You're
very welcome. James (Salty Dog)> Christine
Scratches on Acrylic Tanks Hi Bob, <Good morning! Steven
Pro in this morning.> I have an old 125 gal. acrylic tank with
scratches from rocks falling and coral pieces bumping into the tank.
<A common problem with this material.> How do I remove the
scratches? <There are various products on the market for
buffing/polishing the acrylic to like new status.> The tank is empty
now, <Which makes this procedure much easier.> and has been torn
down for about a year. I would like to set it back up but I would like
to try to make this tank look like new. Any information would be
greatly appreciated. Thanks Kevin Shimabuku <Check out any of the
dry goods e-tailers for acrylic repair/polishing kits. -Steven
Scratches (acrylic repair) Hi Bob, I have a 300 gallon
acrylic reef tank that has a few scratches in it. I ordered some
MicroMesh scratch remover pads from an acrylics shop on the web that
can be used to "polish" out the scratches without using any
scratch remover compound. Is it safe to use these polishing pads inside
the tank to buff out the noticeable scratches in a small area ?
<Yes... but does require that you lower the water level below the
area to be smoothed out. Bob Fenner> Thanks, Chuck Spyropulos
Acrylic Do you know of any way to buff scratches out of an
acrylic tank? Thanks! :) <Yes... have spent a bunch of time trying
to do so... slight liquefied abrasives, to papers to "heat
burnishing". Please use the Google search tool on our sites
homepage or indices (on WetWebMedia.com) with the terms "acrylic
repair" or "scratch removal". Bob Fenner> Elizabeth
Acrylic Scratches Bob- <Scott F.
here this afternoon> I recently purchased a 65 Gallon acrylic tank.
Not thinking I scrubbed the inside of the tank with a Scotch pad
(green, abrasive cleaning pad). <Made that mistake before,
myself!> I then installed my power compact lighting and turned it on
and to my dismay I saw that I have tiny surface scratches all over the
inside of the tank. Is there anything I can do to remove them? PLEASE
HELP ME! Thanks, Mike <Well Mike- this has happened to just about
everyone who's ever had an acrylic tank- so don't beat yourself
up over it. There are "repair kits" available to remove
surface scratches, but they do involve sanding with various grades of
specialized sandpaper. The scratches can be removed, but the work is
kind of tedious! Do consult the dealer where you purchased the aquarium
for a source of these kits, then get to it! Good luck!>
Need help please (scratch, opacity from
acrylic tank repair) hi bob I bought a 60 TruVu tank and had a
scratch in it my LFS gave me some srk-1 to remove it now I have a big
smudge is there some thing you can suggest I can buy to polish that out
thx for any info <There are "finer" polishes (often
scratch-removal kits come with more than one grade) to "polish
around" such hazy areas... in a pinch, if the area is small, you
can even use a gritty oral dentifrice (aka toothpaste) and a soft rag
to buff out such blemishes. Bob Fenner>
Acrylic Nightmare Hi, <Hi there! Scott F. with
you> This is in response to a prior FAQ. I have an empty 55 gallon
acrylic tank that's in need of some serious scratch removal. I
wanted to know if the headaches in trying to do this myself is worth
it. I've seen a few of the various kits that are available, but I
want to know if there's any one particular kit that is recommended
over another. If it's feasible, I'd like to get the tank
professional restored but I don't have any clue where to take it. I
live in the Orange County/Los Angeles area. Please help! Thanks so
much.--Chris Sartor <Well, Chris- "worth it" or not is a
relative term, I guess. Depending on the severity of the scratches, it
may be almost impossible to get 'em all without days on end of
work. I won't kid ya- it's a very tedious process, and if
you're doing a lot of scratches, it can become a "lost
cause" at some point. However, if you have the time, and don't
mind the effort- you can certainly pick up a tank at a good price and
get it quite a bit nicer than it is now. As far as having it
professionally restored- this may be one of those things that make it
not worth the $$$. If you can find someone who can do it, they may
charge enough to make purchasing a new tank look attractive! I'd
try contacting a manufacturer or two for possible referrals. In the LA
area, I think you could call Advance Aqua Tanks (Clear For Life), and
see if they have some ideas. Good luck! Regards, Scott F>
Scratching His Head Over A Scratched Tank! Aloha WWM Crew,
<Howzit? Scott F. with you today> Thanks for all your help. The
service you provide is second to none (no ka oi). <Thanks for the
props! Glad to hear that we've been helpful for you!> I have
written a few times about my 55gallon FOWLR. I'm thinking about
purchasing a used 200 gallon acrylic tank, but I have some questions
before I jump into such a big investment. First, the tank has many huge
scratches on the inside as well as the outside of the tank. The current
owner has many kids that destroyed the outside of the tank. <Those
darned kids... :)> There are so many scratches that you can barely
see into the tank. The tank is a SeaClear and seems to be in good
condition minus the scratches. <An all too common problem with used
acrylic tanks! But also a common reason why used acrylic tanks can
sometimes be had for cheap prices!> I was wondering if the tank
would be worth the headaches of trying to remove all the scratches. Are
there any other issues I need to be aware of? Could the scratches lead
to a leak or cause the tank to crack? <Well, Jeff- if they are
basically surface scratches, they can actually be removed with a
special sandpaper kit made especially for this purpose. It is a rather
tedious process, unfortunately...but it does work! As long as the
scratches are not "deep", or near the seams, then the tank is
probably structurally sound...Do check on the condition of the chemical
"welds" on the corners of the tank, to make sure there are no
signs of them pulling away from each other. As long as the tank is
structurally sounds, and as long as you're up to the challenge of
sanding away the scratches (and if the price is damn good!), you may be
able to score a killer deal on a tank that you can get lots of usage
out of. Do check our sponsors for these acrylic refurbishing kits.
There are other places on the net that offer these special grades of
sandpaper. It's worth a shot.> Mahalo Nui Loa-Thank you very
much, Jeff <Malama Pono and Ahu'i Hou! Regards, Scott F>
Acrylic tank cracks? (crazing) >Hi all at WetWebMedia,
>>The crew says hello, Marina at your service. >First I must
confess your website has been a great help to me for the past year in
looking up what to do when in doubt with my current trigger FOWLR set
up. >>What a confession. Now, what penance...10 lashings with a
wet noodle, then eat the noodle. >Now, on to the point... >>Oh
yes, there was a point. Having too much fun, back to work! >I have
recently purchased a used acrylic tank 76 1/2 x 15 x 30 (made by a
local company). The tank has an overflow to the left side and that is
why it is longer than 72 inches. Total volume is 150 gallons. Now, the
previous owner had attached a piece of plywood or strip of wood across
the upper edge of the tank to support a DIY canopy. While I was
cleaning the tank I removed the wooden strip which was attached with
adhesive tape. Immediately I noticed a series of parallel marks that
looked like cracks on the outside of the tank. There are 3 clusters of
less than an inch marks/cracks on the upper side (roughly half an inch
before the brace starts). I'm not sure whether I caused that my
pulling the wooden piece , or whether it was there from before and the
previous owner had attempted to conceal it. >>Bingo, I think it
was there and he wanted to conceal it. >Also, the same marks appear
on the back side of the tank along the upper side but they are not as
long. This leads me to believe that I did not cause the damage (if it
is to be perceived as damage). Do you think if filled with water, it
will cause a leak down the road? >>Very well could be a problem.
I have a recipe for filling such "tight" cracks (please,
please, let's keep it clean here), but have never used it on a tank
that is so peppered with these cracks. >Should I make arrangements
to have it repaired, or sell the tank? This will be a FOWLR tank with 1
niger, black patch, blue line triggers. Currently, all are at 3-4
inches long. I would greatly appreciate an opinion on this...keep up
the good work on WetWebMedia. >>Well, if there is someone who can
make good repairs and they can price them out for you, allowing that
the repairs are not going to end up costing you the price of a new tank
then I don't see why not go that route. I would first fill the tank
in my yard, on a flat area, to determine several things. First: is it
going to leak? Second: are the cracks just so unsightly that I
don't want this as a display tank. Third: are the repairs proposed
(my recipe will only stop leaks, you'll still be able to see the
cracks quite well) cost effective. At this point, only you can
determine these things, then go on from there. >>My recipe for
repairing these cracks is that you must first ensure that they are
completely free of any and all debris, including any mineral/salt
deposits. Once the cracks are to a pristine state, you need on hand
liquid cyanoacrylate (Superglue) and the catalyst used for acrylic
nails, and a small metal stick (like the tool used to push back
cuticles...hey, I'm a lady!). What you want to achieve is to get
the Superglue to seep into and fill the cracks completely, then
IMMEDIATELY place a drop or three of the catalyst onto it. These
substances react with each other (the hotter and drier the weather, the
more immediate and extreme the reaction) to fuse with the each other
and the acrylic to form a tight bond. However, as I said, you will
still be able to see the cracks--this is a method I've used on
non-display tanks only. >>Good luck! Marina Location of marks
"""" """ "" | Hope this
helps to visualize | | what I wrote above. | | | | | | | | | |
_______________________________________________________ <-- front
panel. Front panel 1/2 inch thick. Bottom panel is 1 inch thick.
Acrylic tank cracks? >Thanks for replying Marina,
>>My pleasure, Dimitris. Well, I called the LFS that sold the
tank to the person that I bought it from and the local guru there said
that if those clusters of lines are not close to the seams or corners,
I shouldn't worry about it. He said I might want to buff it with a
3500 rpm electric drill, but he thinks due to the thickness of the
front acrylic panel( 1/2 inch) that it should be ok. Personally, I
could not see any of those surface lines |||| |||| |||| extend past the
surface. They had no depth, just like those spider web like ones on the
back panel. I guess I will fill the tank up with water to see if it
will leak. >>By your description, it sounds as though the only
problems you'll have will be cosmetic. C'est la vies!
Tough acrylic cleaning question I have purchased an acrylic
tank from a friend. He had applied some clear shipping tape to the
openings in the lid. I have tried elbow grease and my credit card but
the stuff just isn't coming off very well. I've looked around
on your site and didn't find anything appropriate to my situation.
I know not to use Windex or anything else ammonia based. I've
thought about goof off but that's petroleum based. Do you have any
ideas. Thanks <I would try "citrus based cleaners" here
first. Do with the tank empty and make sure and wash any residue from
the surface. Bob Fenner>
Re: tuff acrylic cleaning question, repair Thanks Bob, I
ended up having to use lighter fluid to clean this stuff off, it was
caked on pretty good. <As long as you're "right there"
wiping off the excess (so it doesn't melt the acrylic) this works
pretty well> I have another question. I found two small chips on the
corner of the bottom plate, about 1/4" around and maybe 1/8"
deep. The acrylic is 1 inch think at that location so I don't think
it will be harmful. Do you think that I can put some acrylic glue in
the chip just to give it some strength in that area. <Might help.
Have you considered adding some "square doweling" in the
corner. This stuff comes in stock sizes with two of the four sides
"square" and the other two a bit concave. You solvent (as in
with Weld-on) the two flat sides to the tank inside corners. Bob
Scratch removal and polish on inside of tank using Novus
products Great site for info! I have a Tenecor 180 gallon acrylic
tank that has numerous fine to moderate scratches in the upper half of
the tank as a result of five large red hooks bouncing off the front
panel when it tries to compete for food against a 20 inch jardinei.
<Neat> I am removing the red hooks and want to remove the
unsightly scratches inside the tank. Tenecor sells a group of products
called Novus #1, 2, and 3 that is supposed to remove these scratches,
as well as a micro mesh kit that does the same. <I have used these
products. They work... but the micro mesh reminds me of the Karate Kid
series of movies... rub on, rub on... and takes about as long to remove
the finer scratches it makes as re-watching the whole series!> In
doing the scratch removal, I would prefer to use the Novus products The
micro mesh kit seems very tedious and I do not feel comfortable with
the acrylic particles being sanded off and mixed in with the water and
substrate. <Me neither> But is it safe (non-toxic) to use Novus
on the inside of the tank after the water is taken out of the tank to
the level of the lowest scratch; or am I stuck using the micro mesh
sandpaper? <I'd try the two grits of the Novus first> If I
can use the Novus product inside the tank, is there additional prep
needed after the scratches are removed and the front panel is polished,
before I can refill the tank? <No further prep... just wipe up the
bits of "scum" with a damp paper towel> Thanks for the
help! Steve <Thank you for writing, good luck. Bob Fenner>
Re: follow-up on removing scratches in acrylic tank using Novus,
and visit to Phoenix Thanks, Bob, for your very prompt response! It
is comforting to know that your experience shows Novus 1, 2, and 3 can
be used on the inside of an acrylic tank without harm to the fish. I
bought the Novus 1, 2, and 3 yesterday afternoon. <Wish I had made
these products!> As a follow-up to my earlier email to you, can I
leave my large jardinei in the tank while I am working on removing
scratches with Novus 2, and if necessary, Novus 3. That is, from a
chemically (nontoxic) safe standpoint? <As far as I'm aware,
yes. Have used these in "full tanks", fresh and marine, with
impunity> There will be about 4 inches of water for him to stay wet;
<And not jumping out!> the lowest scratch to be removed is an
inch above this water line. Thanks in advance for your advice! BTW,
Phoenix has a dry heat this time of year ... and its been mild this
week. Its the August monsoon that you want to avoid. Steve <Will be
out there this Thursday with some friends/associates, giving a pitch at
the DMS (Desert Marine Aquarium Society). Stop by if you'd like.
Acrylic Tank Scratches Hello all: <Hi there> Just a
real quick question so I don't botch things up. We have a 125G
acrylic that has developed some scratches on the front panel. I must
have failed to notice a tiny bit of gravel in the pad while cleaning,
as I am vigilant about making sure that no debris is in the pad before
I use it on the panes. <Good idea> Nonetheless, I went on the
website and found Bob's response to a similar query, where he
recommended using a gritty toothpaste to remove minor scratches. I was
wondering if this procedure can be done while the scratches are under
water. I can apply the toothpaste without any difficulty, as the
scratches are within arm's reach. However, I am very concerned
about the effects, if any, that the dissolved toothpaste may have on my
fish. Thanks for the clarification. Mitch <Mmm, they may end up with
"whiter, brighter teeth" and a "significant reduction in
dental caries", but should otherwise be fine. Bob Fenner>
Re: Acrylic Tank Scratches Thanks, Bob...I am sure that my
porcupine puffer, with his sizeable bite, will appreciate the brushing!
I will try and get a paste that is recommended "by 4 out of 5
members of the American (Fish) Dental Association." Mitch <Ha
haha, heehee! Be chatting. Bob F>
Acrylic Scratches A few months back you mentioned a way to
remove scratches from acrylic aquariums even under water. Due to travel
requirements I was out of town for the next few days and missed it if
you elaborated on the subject. I have checked the web site I was
directed to by Bob but still haven't found any specific
instructions. Can you please help me out? Thanks <Alright, I hope
you can find this one! Most scratches can be polished out, depending on
depth.... There are kits available from most on-line suppliers carrying
acrylic tanks that use abrasives in finer and finer grades to remove
the scratches and restore a lustrous finish, even under water with
some. You might start by searching for these products at some of our
sponsors! Thanks for your patience.....Craig>
Invertebrates that scratch acrylic tanks 5/11/03 Hi can
anyone tell me which invertebrates can scratch my new acrylic tank? And
which ones won't do any damage to the tank? Thanks, Ron <mostly
limited to mollusks with a radula (hard rasping tongue-like aspect-
Gastropods predominate.)... and some echinoderms. Generally not a big
deal. Best regards, Anthony
- Scratches in the Acrylic - I have an acrylic TruVu aquarium
and it is scratched on the outside and looks hazy in some parts. What
can I do or use to take these scratches out? Yoquin <There are
several commercial 'acrylic scratch-repair' kits out there.
Look on the online retailers and you will find them. Cheers, J --
Coralline Algae and Acrylic Aquariums 1/14/03 Hi Bob or
Crewmate, <Hi Joseph. Adam here tonight.> I haven't even
received my custom acrylic tank and I'm already fretting over
scratches. Bob, in his book The Conscientious Aquarist recommended
acrylic tanks over glass. I just started reading The Reef Aquarium and
Delbeek and Sprung suggest that acrylic tanks are more suitable for
fish only because cleaning the coralline algae off the walls will
scratch the acrylic due to the calcium. <A question for the ages!
Some folks swear by acrylic, some swear at it! Acrylic is a better
insulator, is clearer, is lighter and is more shatter resistant, but
scratching can be an issue.> Just how much of a problem are
scratches with an acrylic tank? If I am careful and use the proper
tools to clean the tank, will I be able to enjoy watching a marine
environment in my home for many years without seeing obvious scratches
on the acrylic panes? Even though I am willing to invest substantial
time, energy and money in setting up and maintaining a reef aquarium, I
am not willing to do this if, after a few years, I am seeing a
scratched viewing panel first and a reef second. I would just as soon
fill the 145 gallon tank up with freshwater and goldfish. Thank You,
Joseph Rouse <There are a few tips for keeping acrylic tanks scratch
free. First, clean it often to prevent heavy build up of coralline (a
cleaning magnet is a great aid here). Second, be very careful to use
acrylic safe tools and don't trap any sand or grit in the tool.
Lastly, just be generally careful in how you work in the tank, place
rock, etc. There is no doubt you will get some scratches, but under
water they are nearly invisible and shouldn't detract much from
your viewing pleasure. Best of luck! Adam>
- Acrylic Scratches - Good morning, My question is as
follows: I have an acrylic tank and while I was setting it up a few
scratches appeared inside the tank and I would like to know how I could
polish it, I have read about a tool called router, but I have no idea
if it is the tool I need or if I could introduce it inside the water.
<A router is not your friend in this endeavor and in fact the only
power tool practical for such things is your own arm-power. There are a
number of scratch-removal kits which involve fine grade abrasives...
some can be used wet, others must be used dry. Both types are available
at most online retailers. You find however that it takes longer than is
practical with less than satisfactory results... you might just want to
get used to the scratches.> Thank you very much. Jorge <Cheers, J
Can Some Fish Scratch Acrylic? Bob, <Yes> I have read
at one website that some fish will "mouth" the sides of an
acrylic tank and make scratches. The fish listed included angels,
butterflies and triggers. Is this something for an acrylic aquarium
owner to be concerned about? Joseph Rouse <Mainly just some of the
tetraodontiform fishes (triggers, large puffers)... but compared to
other sources of scratching (mainly aquarists with cleaning tools,
trapped bits of gravel...) no biggee. In the world of possibilities,
this is minor spuds. Bob Fenner>
-Removing scratches from acrylic tank- Hello, I found your
site while trying to figure out what to do with my 60 gal tank.. My
wife was trying to be helpful and scrubbed the inside of my acrylic
tank with one of those sponges that have the green scotch pads..
<Ouch!> Needless to say, the front of the tank now has a
"clouded" look to it.. We have since moved from So Cal, to
Grants Pass, Oregon.. While the tank is now drained I'd like to get
the scratches "polished" out.. I have read of the product
called "Novus" on your site.. Is this something I can do
myself? <Absolutely, and I hear it works wonders.> Or is it
something I have to have a supplier apply? Is there any supplier in the
Grants Pass, Oregon area that I can purchase this from? <No idea,
but I did find an e-tailer that carries it http://www.tropicalfishstore.com/careproducts.htm>
Any help will be much appreciated! <Good luck! -Kevin> Thank you,
Removing Scratches on tank Hi, <Hello there> I love
your web site (Bob along with the WetWebMedia crew, along with your
book. It has helped me so much in my years of reef keeping. <Ah,
good. Our intention> I am, however, puzzled by one question. Whether
or not I can actually use the Novus product underwater? <Mmm, no...
you must drain the tank down to below this point... though some water
may remain in the tank... and the livestock too if there is enough
space for them> In one post you claim it can not be used, and in
another you claim it can. I have cited each for you below. I know that
toothpaste method works for certain to remove light scuffs inside the
tank, I have done this several times without any ill effect. I just
wonder how safe Novus 3 or Novus 2 would be underwater, in a fully
stocked reef with corals, fish and inverts. I would hate to blow
thousands or dollars just to remove a scratch. So, which do you
recommend, using Novus underwater, or not using it underwater. Thank
you in advance for clearing this up. Jon <Sorry for the confusion.
The second piece is not clear, but it is my intention to convey that
the product itself is NOT toxic if it gets into the system/water to
some extent (have done this myself), but does need to be worked,
rubbed-in in the air... that is, with the tank drained down or emptied.
No problem with some of the resulting "dust" getting into the
water though. Bob Fenner> Taking out scratches from the inside Bob,
Do you know of any acrylic scratch removal kit that works underwater?
<No... all require draining the system at least down to the level of
the work. Bob Fenner> Thanks, Lee Re: follow-up on removing
scratches in acrylic tank using Novus, and visit to Phoenix Thanks,
Bob, for your very prompt response! It is comforting to know that your
experience shows Novus 1, 2, and 3 can be used on the inside of an
acrylic tank without harm to the fish. I bought the Novus 1, 2, and 3
yesterday afternoon. <Wish I had made these products!> As a
follow-up to my earlier email to you, can I leave my large jardinei in
the tank while I am working on removing scratches with Novus 2, and if
necessary, Novus 3. That is, from a chemically (nontoxic) safe
standpoint? <As far as I'm aware, yes. Have used these in
"full tanks", fresh and marine, with impunity> There will
be about 4 inches of water for him to stay wet; <And not jumping
out!> the lowest scratch to be removed is an inch above this water
line. Thanks in advance for your advice! BTW, Phoenix has a dry heat
this time of year ... and its been mild this week. Its the August
monsoon that you want to avoid. Steve <Will be out there this
Thursday with some friends/associates, giving a pitch at the DMS
(Desert Marine Aquarium Society). Stop by if you'd like. Bob
Removing Scratches From Acrylic Aquariums I just recently
purchased a brand new Sea Clear Acrylic aquarium and when I was
fumbling around with my rocks in the aquarium I noticed that the
acrylic was scratched rather easily. It was very disappointing since
this was a new tank. <I can relate! I love my acrylic tanks; swear
by 'em for strength, but I hate the scratch aspect!> Scratches
are rather light, I realize now that acrylic SCRATCHES very easily.
<Yes, it does! Be careful, also, if you use a magnetic "algae
scrubber", and have a fine bed of sand. These magnetic scrapers
can pick up bits of sand on the pad and leave full-length scratches! I
know, 'cause I've had it happen, myself!> My question is, is
there any way to remove light scratches on acrylic or are they pretty
much permanent? Is there any method or product that I can use or a web
site that you can refer me to that may help me out with removing these
unsightly scratches? Thank you very much for any information you can
provide. Love the site. <Well, there is an "acrylic scratch
removal kit" by Rainbow Lifeguard (now Pentair Aquatics), that you
can get online from Dr. Foster & Smith, among others, which
consists of varying grades of fine grit sandpaper, used one after the
other, getting progressively finer. It takes a lot of patience, and you
must be very careful, but it does work. Hope this helps! Regards, Scott
Acrylic tank Hello, <Hi Audrey, MacL here with you
today.> Sorry to bother you but I found you on a search and wanted
to ask you a question. I just bought a used Acrylic 60 gallon tank. I
was so stupid and cleaned it with a ......... and now my tank is very
dull. <Acrylic tanks get scratched extremely easily and some
chemicals "burn" them. Its pretty easy to restore the shine
though. I'm assuming the tank is still empty. I personally have had
good luck with the Novus products. They have several types of
polish.> What do I do?? <Find a plastics store in your local
phone book and ask them if they carry the Novus polish products. I
think you are going to need all three of them to bring back your
tank.> Please help me. <Hope that helps. MacL> Thank you,
Toxicity of Sea Clear acrylic scratch remover Is Sea Clear
acrylic scratch remover toxic to fish-can it be safely used inside the
aquarium to remove scratches? Thank you, Sue Kennedy :) <Not very
toxic... so okay to have bits fall into the water, but best to lower
your water low enough and remove the residue after rubbing as much as
possible. Bob Fenner>
|Picture of crazing I read your Q and A section about
acrylic aquarium repair and my question was about crazing. Mr.
Fenner stated that one should take a picture and ask an expert to
take a look at it so what do you guys think??? <This is...
crazing for sure> should I scrap it or is there some way to
repair this monster it's 240 gal standard this is the only real
tank flaw it's about 3 or 4 years old. please tell me I can fix
it <I wouldn't scrap the tank... for fear of it rupturing...
if this is all the apparent stress cracking there is. If it worries
you, solventing a thin sheet/piece of acrylic over the area (with
the tank empty) may render the crazing less conspicuous while
adding strength. Bob Fenner>
|Re: picture of crazing Thanks so much I really
appreciate your advice I think I am going to melt a little acrylic
on there you can't really see it when the hood's on. my
concern was more structural. Thanks again Mr.. Fenner
<You're welcome my friend. Bob Fenner>
(Damaged) Acrylic tank assessment 7/4/05 I am sorry this is
such a long post. I just don't know what exactly is pertinent
information, so when you know enough just stop reading. Reading the
posts made me think really hard, and try to be perhaps too observant. I
posted here because you seemed to know a lot about tank integrity.
<Okay> I brought home a free acrylic (I think, are there other
plastics for tanks?) <Mmm, really only very small ones... acrylic/s
have many names, are about all of the same composition> tank today.
It is a TruVu brand, 16 deep 18 wide 60 long. There are cracks in the
top and I don't know the owner (neighbor of an ex-boyfreind), so I
can't get the history of the tank. It looks like it belonged to a
fraternity (stickers and spray-paint and graffiti). My ex- did say he
was told it doesn't leak. <Actual cracks or just crazing? Can
you feel breaks in the material? These are indicative of cracking> I
am afraid it will fail. I am not concerned about a slow failure, I am
afraid that some of the cracks will just split with no warning after
the tank is in use some time. I also see what I think is some crazing.
<Ah, I see> I haven't filled the tank to test it because I
wonder if I should repair it first. The link to the repair story is
broken, so I couldn't read it. <Unfortunately there is no such
piece... just haven't gotten around to writing it...> If there
is a quick easy fix that may hold this tank together, I will do that
first. <It may be that the cracks can just be ignored (fill this
tank outside and see how it does), otherwise, the solvent used to weld
the tank panels together may be used to anneal the cracked portions
(call, write TruVu re Weld-On...). At worst, another panel (thin) of
the same size, cut-outs may be solvented to the top/cracked one>
CRACKS: These may have been produced by heat, as I read in other posts.
My reasons for thinking so are that the top of the tank is warped, and
there is a small area of the top that looks like it may be air bubbles.
Does acrylic "Boil" from heat? Also, the edges of the cracks
are warped and do not match each other. <Warping is common... these
tanks bend quite a bit with use/time... boiling is very bad> If the
cracks were caused by heat, might the tank be compromised to the point
that it will fail, because the top is an important structural member?
<Doubtful, but a possibility> My reasons for thinking it is not
heat is I do not see any blackening or discoloration. Also, one crack
actually extends down the side of the tank about an inch. Could this
crack be from an impact? <Yes, most likely... am starting to have
glimpses of "Animal House"> I haven't filled the tank
to test it because I wonder if I should repair it first. The link to
the repair story is broken, so I couldn't read it. If there is a
quick easy fix that may hold this tank together, I will do that first.
There are four cracks in the top of the aquarium, they all run from a
corner of the large cut out to the side of the aquarium. <These are
best repaired per above> The two in the back run from the side
cutout to the 1-1/4 diameter hole, to the back of the tank. One
CONTINUES down the side of the tank about an inch, this portion of the
crack is not perpendicular, but actually at an oblique angle to the
tanks surface. <Also best repaired> The tank top has two
rectangular cut-outs, two smaller rectangular cutouts, six 1/4"D
circular holes, and 2 circular holes about 1-1/4 "D. One of the
1-1/4 inch holes is not really circular, it looks as if a smaller hole
was drilled off center of the larger one, however the edges are nice
and smooth, so I don't know if these holes were homemade, or poor
quality control of the manufacturer. But the crack is not located near
this bump. CRAZING: It is a really sunny day and I noticed when looking
obliquely at the tank outside that there was a glittery sheen inside
the acrylic. It seemed to be pretty uniform throughout the back surface
of the aquarium, and I did not see any direction to it, just little
spots of glitter. I could not see them on the other sides of the
aquarium, but this could be because I did not turn the tank to the same
angle. I suspect that it is crazing. (If not, what could it be?)
<Likely crazing... though could be marks from solvent, local
pressure or heat stress> I cannot see it at all when the aquarium is
viewed straight on. And I don't think I could see it in indoor
lighting. Is a certain amount of crazing a normal occurrence? Does it
happen in every tank? <Is common> USE: When I first saw the tank,
I thought that it wasn't very useful for a display tank. Now I am
thinking that it actually would look pretty funky as a type of urban
community tank. What do you think of this idea? Thank you, Mary <If
you have the time, interest, worth trying to effect a repair. Bob
Re: Acrylic tank assessment 7/6/05 Thank you for your reply.
I was unsure about how to weld the cracks closed. The edges don't
line up, and in some cases, the irregularities of the edges get in the
way of realigning the acrylic. I took the tank into TAP plastics today.
They suggested that I drill a small hole at the end of the crack before
I weld. This will relieve any stress at that point from the
misalignment. <Interesting> This makes sense. (Lucky that all the
cracks end one inch from the top.) It is consistent with the reason
that larger diameter corners are stronger, the stress is distributed
over a larger area. <Yes> The weld-on #16 cost $3.05. The piece
of scrap would have been $1, but he threw it in for free. Must have
felt sorry for me, trying to save such a pitiful tank. He should only
see my car! LOL! <Likely> He thought the warp on the cross member
would not affect its strength, and that I don't need to reinforce
it. <Okay> He had no idea about the crazing unless it was a
solvent. I suppose its possible the gut tried cleaning it with
something weird. But I really don't think so, it is so evenly
distributed. <Is just "stress" over time mainly> I just
wanted to share with you the idea of drilling. Wow a 75 gallon tank for
$3.05! I'll let you know how things go with my experiment.
<I'd appreciate this> I will drill the holes, wash the tank
(soap and water he said) <Mmm, no... avoid soaps, detergents...
toxic to aquatic life, hard to remove, leave a film... water and
vinegar, possibly straight vinegar (white) for "scale"...>
and weld a piece of scrap over each crack. I am toying with the idea of
welding an acrylic divider in the middle to compartmentalize it into
two tanks, but I haven't decided yet. <Mmm, worth considering...
but hard to change later> I would prefer a removable divider, but
since the acrylic will flex, I don't know how I could do this.
<There are commercially made dividers, but these are a bit flimsy
for this sort of tank> Right now I really could use smaller tanks.
Well its time to stop blathering, and see if this idea will hold water!
Mary <Real good. Bob Fenner>
Ready to raise the white flag... scratched acrylic tank
7/19/05 Hey guys, I have a 65 gal. acrylic tank that I bought used.
When I bought it, I was under the impression that scratches are
relatively easy to remove, as it says on your and every other site
around. <Uhh, not easy to remove. For my part, I apologize if WWM
has left/given you this impression> I tried using a Craftics 20/20
scratch remover and polish kit and had no such luck. Sad to say the
tank is now even more scratched than it was before. Furthermore, the
thickened acrylic cement that North Coast Marines recommended to fill
in a small gauge actually made the tank worse. If acrylic scratches are
easy to remove, what am I missing here? <Nothing... just lots of
labor, possibly (yes) power tools> I spoke with a professional
reglazer who wants almost as much as I paid for the tank to reglaze it.
Between this and the fact that the equipment I got with the tank
doesn't work right and isn't even exactly what I need-- and
that is completely and totally entirely my fault--I am ready to throw
in the towel. I'd like to keep going, but I just can't afford
to absorb this kind of a loss and still pay for all the other equipment
I need. I did a lot of homework before I bought anything but apparently
not enough. I'm not holding out much hope, but is there some way to
fix this without sinking several hundred more dollars into it? I have a
funny feeling this is the end, but with an answer to this question, I
can at least say I've exhausted every option. I want to thank you
guys for the help you've provided me with. You've all really
been great. Thanks again, Marianne <Mmm, I'd hold onto this
tank... use it for "back-up", maybe mixing, storing water...
possibly as a sump/refugium for a large/r system down the road. Bob