FAQs on Glass Aquarium Repair, Chips/Cracks 11
Acrylic Aquarium Repair,
Marine Tanks, Stands and Covers,
Used Gear for Marine Systems,
Designer Marine tanks, stands and covers,
Glass Aquarium Repair 1,
Glass Aquarium Repair 2, G lass Aquarium
Repair 3, Glass Aquarium Repair 4, Glass Aquarium Repair 5,
& FAQs on Repairing Glass Tank: Scratches/Blemishes, Cross-Braces, Leaks, Whole
Panes, Tools: Cutting Glass,
Silicone, Moulding/Frames; Techniques; Olde Tank (Slate Bottom, Metal Frame,
Pecora...) Repairs, Troubleshooting/Repairs, &
Repair, Used Aquarium
Chipped tank 8/1/18
<Good morning Rialda>
My 90 gallon tank sustained some damage during a move. I filled it with water
outside and it is not leaking.
<That is because the crack is almost at the top where there is less water
The size of the chip/crack is worrying to me though.
<Crack will extend in time for sure if you leave it as is>
Is this tank a write off as an aquarium or dare I set it up again inside the
< If you replace the front panel, you may set it up inside the house with
This what it looked like two weeks ago when it happened:
And here is what it looks like now, it seems to have grown.
<Please send images of only a few hundred KBs otherwise you may crash our
server. I resized them>
Thank you kindly for any advice and help you may be able to give me.
<Glad to help. Wilberth>
Crack in fish tank 7/26/18
Your site came up when I searched. About three weeks ago we moved our reef tank
contents from 180 to 240 gallon tank - the 240 is a brand new 1/2" glass
commercially built tank purchased through our LFS. Just noticed last
night a internal crack about 1-1/2 inches in bottom front corner - have pictures
- are you able to offer your opinion about this?
<Um, yes. Please search, read the many posts on WWM re ahead. Bob Fenner>
Re: Crack in fish tank 7/26/18
Here are three pictures - Haven't talked to the LFS yet - they delivered,
brought in, and setup (moved everything from old to new) the tank. No one
noticed this crack at the time.
Thanks very much for your thoughts about this!
<... this is a very bad break, in the worst of places. I would DRAIN
this tank down NOW. There are external and internal repairs that can be
made; and gone over and over on WWM. B>
Re: Crack in fish tank 7/26/18
Thanks for your input. After reviewing a number of other chip and crack
assessments at the WWM site I was somewhat prepared for the bad news.
<Yes; sorry to be the bearer of bad news... BUT this is a bad break: Dangerous>
Will be stopping in at the LFS after work today to show them the pictures and
<Ah yes; but "these things do happen">
Ironically we did this switch because our original (20 years old) 180 gallon
tank had developed a leak...
<Be of good cheer. BobF>
Hi, I purchased my first big tank about a week ago at PetSmart. It is a 65
gallon Aqueon glass aquarium and it came with a stand, hood, and light.
Yesterday I was adding the substrate when i noticed a small chip that is causing
me to lose sleep. I do not think i bought it like this, I must have hit the
corner of the wall or something. I am hoping that with the pics attached you can
help me decide whether or not it will hold up for at least a couple of years. I
was also wondering if chips like this will affect the "lifespan" of the
<Mmm; this is an "iffy" break. Good that it's high up, in the shallower part of
tank depth; but bad due to size and span of the corner. Will the vendor take
this tank back, exchange if for another (non-chipped) one?
Re: Chipped aquarium 7/3/18
Thanks Bob, I went to the store today and had a chat with the fish people.
They were very nice and said I should call tomorrow to set-up an exchange.
<Ah, very good indeed>
I will definitely look over this one before bringing it home, as i feel
dishonest in returning something that i probably damaged. Thank you for your
Acrylic tank HELP 5/13/18
I noticed some splotches on the used acrylic tank that I recently purchased. I'm
wondering if I should be concerned about them or not.
There are also some small visible Nick's that I can feel with my finger nail.
I'd really appreciate your help. Thank you so much for even having the FAQ.
<The "whited out spots" in the joint of the tank aren't problematical. Do keep
an eye on them over the years to make sure they don't grow; make up more than
half the joint. The vertical fracturing/crazing you are likely referring to as
noticeable w/ your finger nail is more concerning. IF you find yourself at a
time with the tank empty, dry, completely clean, I would solvent a piece of
doweling or cut piece/sheet of acrylic in this corner... the entire length of
the crazed side. Do you understand? Please read re on WWM. Bob Fenner>
Hello! Chipped tank corner question 4/30/18
I’ve read many articles of yours and they have been very helpful, was hoping
y’all could give me some info in an issue I ran into. While cleaning near tank
this morning, clipped outside corner with a bowl and made a tiny “seashell” type
chip on the outside corner of tank.... is this something I should be worried
<Mmm; well; just a little. Am concerned in that I can't tell whereabouts this
chip is... better to be near/er the surface, top.>
Thanks! Pic attached as well, thanks again for any help! It’s a 56 column tank.
If not a big deal was going to silicone and put a surface mount thermometer over
<Yes to the Silicone and thermometer... If it were me, mine, I'd go ahead and
keep using this tank. The concentric chipping looks clean, regular... not too
likely to splinter>
(Quarter for size reference)
<And you, Bob Fenner>
Re: Hello! Chipped tank corner question
Thanks for the quick response!
I truly appreciate it, have a great Sunday ��
<Welcome. And you Steven. BobF>
Need advice urgently 4/13/18
Good evening guys
<Hey only going on three in the afternoon here!>
I have a 1.5meter Boyu curved tank which I was busy taking into my house and I
accidentally nudged it on the front panel at the bottom , the front panel
overlaps the base so the silicone seal isn’t disturbed
The chip is right through the front panel but the base is still 100% perfect
<I see this, and the placement in your excellent pix>
Do you think I can brace it on the inside of the tank along the front panel and
then put a lot of silicone on the trimming when I put the trimming back on ????
Please advise ..... I don’t know what to do and this tank has cost me an
equivalent of about 1000 US Dollars
<I do think that you'll be okay with the brace, and would fill in the area of
the chip to avoid cuts to your hands>
Thank you guys for helping out guys like myself and for your expert advice
<Cheers, Bob Fenner>
Re: Need advice urgently 4/13/18
Thank you so much for your prompt response , I’m so happy to hear that the
bracing will work as I have asked a few people locally ( I am from Cape Town ,
South Africa ) and most of them say it should be ok but it was just that one
person that commented that it wasn’t going to work that got me panicking. Thank
you so much for your expert advice , it has put my mind at ease now that it will
I will brace it and do a pressure test for a week or two just to be 100% before
I place it in my house ( I will keep you guys posted )
Thank you guys for such an amazing service of advice .
<Cheers Trev. B>
Re: Need advice urgently; follow-up on glass tank repair
Good morning ��
<Bon après-midi !>
I just thought I would give you an update on my tank that you were so kind to
help me out with some advice
The tank has not leaked at all since I set it up.
<Always a good thing when it comes to fishkeeping.>
And is running fully stocked with my all male Cichlid show tank ...... here is a
picture of it now
<Looks good. You might try removing the plastic plants, letting them dry, then
using aquarium silicone to glue on small pebbles or stones. Leave to dry for a
couple days or however long the instructions say. Then put them back in the
tank. Result: not only are the plastic plants harder to move and easier to root
into the sand, they also look more natural, and even if they are uprooted, still
look good. The stones or pebbles will act like anchors too, keeping the plants
more or less vertical and in place.>
Please excuse the wire in the background as I’m having a background made for it
at the moment
Thank you so much for all your advice ..... you guys are awesome ������ if it
wasn’t for you guys I would of thrown this tank away
<I'm sure BobF appreciates your kind words and interest in our website.>
Cracked 46 gal bowfront top side panel
Hello there....first of all, thank you very much for dedicating your time to
help us. Second of all...we (the ones with many questions) are very lucky to
find this place full of knowledgeable human beings (You!)...for which, I have
this beautiful useless fish tank but maybe new well deserve home 3" slider
turtle. Is it safe to create a vivarium kind of home for Dorotea?
<Ah yes; I would feel confident filling this tank about a third of the way.
IF you wanted to fill it all the way, I would Silicone a piece (rectangle) of
acrylic (1/8" or so) over the inside or outside of this cracked area>
If so, should I silicone it or anything else?...IDK,
<Oh! Again, only necessary if filling up more than 1/4-1/3 of the way>
if is safe but I know I love my cute always hungry but not overfed Dorotea and
need to be sure I wont cause any harm just bc I'm trying to be a good
mommy..Many thanks! Greeyt
<Welcome. Bob Fenner>
Glass Aquarium Chip 4/3/17
<Can't open your too-large (8.6 meg file) here at the airport in Roatan
Wyatt... Will do so manana in EEUU. B>
Glass Aquarium Chip 4/3/17
Hello thank you for the support and valuable information over the years. I
am setting up an approximately 92 rimless glass aquarium with 1/2" low iron
glass. After getting this aquarium in place I discovered the chip
The aquarium is new. Any opinions and concerns would be greatly appreciated.
<The size, shape of this chip doesn't worry me (I'd use this tank); but I
might tape over the spot to prevent cutting hands, fingers. Bob Fenner>
Re: Glass Aquarium Chip 4/3/17
No problem I wanted to leave them decent resolution so you can zoom in as
needed. Here is a third party hosted link if all else fails
Re: Glass Aquarium Chip 4/3/17
Thank you again and take care!
<Ahh, will do. BobF>
The best of times the worst of times. Little glass chip and stand
leveling input to share 2/28/17
Hi WWM Crew,
"It was the best of times, it was the worst of times." Sorry to get all
"literary" with you, but it seemed to describe accurately my dilemma. It was the
best of times in that, finally, after four and a half years without a fish tank,
I am ready to get wet again.
The stand was built, the plumbing and sump were worked out in the basement, and
this past Saturday a friend and I moved the stand and tank into the den. I
worked for a couple of evenings on and off getting it perfectly level. I even
learned a couple of neat tricks that I will share below.
The tank is now level and ready to be filled beyond the 2 3/4" that I have
already put in it to level it.
It was the worst of times in that last evening, while I was finishing up the
leveling, I noticed a chip in the front left corner of the tank (see picture).
<I see this>
This tank is a 75 gallon with the overflow offset in the middle of the left half
of the rear of the tank (I think it's an AGA). I got it slightly used four years
ago, and it has been sitting in my basement since then.
When I first got it in the basement, I went over it with a fine tooth comb and
did not see this chip. I'm sure I would have if it had had it then. It must have
happened some time since then. I have also looked over it several more times
since then, but not as carefully. We have been very careful moving it around,
and we didn't bump it into anything any time we
<This is a small "impact" chip, scalloped... IF one had to have one, the better
I've had it filled several times--right after I bought it, to check the stand,
and to check the plumbing/sump. Each time it was filled for several days (once
for a week). The last two fillings were recent (the plumbing check was last
month). I'm virtually certain the chip was there then. I know we didn't bump it
into anything carrying it into the house, and nothing has been bumped into it
since then either. In fact, nothing has been bumped into it at any time (that I
know of). The source of the chip is a mystery.
I have looked over the chip FAQs several times over the years (out of concern
for other tanks for potential sumps/QT's), and looking at the information there,
it is not the nature of the chip that concerns me. It is a "sea shell"
chip with no cracks that is about 1/8" in diameter. It is too shallow
to measure the depth effectively. I tried to take a side-view
picture and you couldn't even see it. What concerns me is where it is.
It is about 2 1/2" to 2 3/4" from the bottom of the tank (measured from
the inside by the depth of the water). It is toward the outside of the glass
panel though (not on the side with the silicon). For this reason, I decided to
seek "professional help" in assessing it.
<I'm not overly concerned re the size, placement>
I don't mind admitting that it makes me nervous. My last marine aquarium was a
55 gallon that the bottom panel burst mysteriously in the night.
Actually it wasn't so mysterious because the stand top was not planar and I
don't think the tank was completely level either (though it was hard to tell
after the fact).
THIS stand is planar with one tiny gap (less than 1/32") on one corner. I have
used 3/4" Styrofoam underneath the tank to solve that problem. The tank is
perfectly level now (with less than three inches of water) and I intend to keep
checking it as I fill it--if I get to fill it, which is what I'm hoping that
your professional eyes can tell me. I think I know the answer, but is this tank
safe to use? Or do I need to save my pennies for another one?
<I would use it>
I also wanted to share a couple of tips that I learned while leveling the tank.
It may be old information to many, but I don't recall reading them anywhere on
WWM. I have read about putting a couple of inches of water in the tank and
measuring the depth to determine whether it is level. What I discovered is that
it is easier to use a yard stick than a tape measure.
Also, I discovered if I put a small piece of painter's tape on the yard stick to
mark where the water depth was when I measured the first corner that it made it
a lot easier to determine whether the other measurements were the same or not.
It was either right at the tape mark or above or below it. I only taped one side
of the markings so I could tell how much
from the other side. Also I discovered that it helped to draw a rectangle
representing the tank from above and write at each corner and in the front and
back middle the depth so I could look at all the measurements at the same time
and decide where the shims needed to go. Hope someone finds this helpful.
<Thank you for sharing>
As always I thank you SO MUCH for making this service available. I have learned
so much over the years from the site and the few email inquiries I have made.
<Welcome. Bob Fenner>
Questions about Sumps and glass tank seams and chips
Dear WWM Crew,
<Hit it Eddie>
It’s me again, and I have a lot more questions to ask you. The test fill
went great. The tank and the stand did fine. I’m still working on the siding
for the stand, so in the meantime, I’m trying to finalize my filtration
plans. The plan all along has been to have a sump and a refugium/DSB, but I
had to wait until the stand was built so I could know exactly how much room
I would have.
The 75 gallon tank has the typical overflow with the 1” drain and ¾”
<Ugh; a one-inch through-put is too small... DO plan on doing most all your
water (re)circulation inside the main tank... with submersible pumps,
However, I intend to use both holes for drains and run the return over the
back of the tank.
<Mmm; well, the 3/4 inch won't do much good. See HERE:
The plan is for the drains to empty into the skimmer chamber of the sump.
<Mmm... better later... in a chamber that has about constant level>
The skimmer is an Aqua C EV-180. Then there will be the typical baffles to
the other chamber of the sump that will have the return pump. Also in this
chamber will be a power head that will pump water to the DSB/Refugium, and
the water will then gravity feed from there back to the return pump chamber
of the sump. That’s the general plan. Now to the specifics and the questions
. . .
I have had a difficult time finding two containers that will fit together in
the stand to use for the sump and the DSB/Refugium. I know I can use either
smaller tanks or plastic storage containers. For cost reasons the plan was
to use storage containers (trying to do this on a budget), but I can’t seem
to find the right size.
<Mmm; even online? Container Store, Amazon...?>
Then, a couple of weeks ago, I went by a LFS in a nearby city (hour and a
half away) that was going out of business. They had a stack of 20 gallon
glass display tanks that they were selling for $5 each. They were each
drilled with a 1” bulkhead about ¾ of the way up the back, and were painted
blue on all three sides. Because they were so inexpensive, I picked one up,
thinking it might work really well for the DSB/Refugium—since it was already
drilled I thought I could use this throughput for the gravity feed back to
the sump. I took it home and put it in the stand and measured the remaining
space for the sump.
Then I made a vain search for a plastic container that would fit with the 20
gallon tank, but couldn’t find one. That left me limited to using a
10 gallon aquarium for the sump.
<Too small; I'd use the 20 for the sump, the ten for the 'fuge>
(The space is too small for a 20 Gallon. Is there a common 15 gallon size?
I’ve never seen one.)
<Oh yes; 24" X 12" X 12" if memory serves>
I happened to have an old 10 gallon that might work (see below), and if it
doesn’t they are not expensive. So the plan is now to put baffles in the 10
gallon dividing it into two chambers. The water drains into the skimmer
chamber and flows through the baffles to the return chamber. In the return
chamber are two pumps—the Mag 7 pump
May well overdrive your over-flows.... Again... I would NOT drive this much
water through.... IF one of the too-puny overflows becomes occluded... water
on the floor>
which will return the water to the display, and a power head which will pump
water to the 20 gallon DSB/refugium. From there the water will gravity feed
to the return chamber through the 1” drain. To make this work I will have to
build a platform to elevate the 20 gallon tank several inches, but I have
plenty of vertical room in the stand.
So, now here are the issues/questions:
1. I am test filling the 20 gallon tank, and there are some bubbles in the
seams (see pictures—these are from the two front corners. The back
corners also have bubbles, but not quite as many). I have no idea how old
the tank is or how long it was used as a sales tank by the LFS. In my
purpose it will not be full at any time—only up to the drain, so about ¾
full—but it will contain a 5” DSB and perhaps some live rock. In your
estimation is it safe to use for this purpose? I can continue to test fill
for as long as necessary. Also, in test filling it I have filled it over the
bulkhead (by turning the elbow fittings up I have filled it a couple of
inches higher than it will be in normal use). So it has a couple of inches
more water in it now than it will have normally.
<I wouldn't be concerned w/ these air bubbles>
2. If the 20 gallon tank is safe to use, what GPH should I look for in the
power head to feed the water to it?
<Small; as in 3-4 turns per hour>
3. In regard to the idea to use a 10 gallon tank for the sump, will this be
large enough to handle the amount of flow and excess water in a power loss?
<Not likely NO. For SURE you want to "test" here... FILL the tanks up, turn
on the pump/s and then turn them off... see how much water "runs down hill",
MARK the sump as to MAXIMUM depth (with a permanent marker, tape) and DO NOT
fill it any more than this>
I know the 1/3 display tank size rule for sumps, but I am counting the 20
gallon DSB/Refugium too, so that puts me at 30 Gallons.
<Mate; ALL the water above the overflow of the main tank PLUS
refugium will have to be accommodated in the SUMP. USE the twenty or keep
looking. You've configured a disaster in the making here>
Also, I am going to put a valve on the return line so that I can throttle
back the return pump if necessary.
<Not a good idea really. Just get/use the size (pressure, flow) pump that
will be on full all the time>
Most circulation will be accomplished through circulation power heads in the
4. If a 10 gallon tank will work, how much minimum space needs to be between
<About... Oh, see this below. Yes to gaps that allow getting a siphon,
cleaning tools into>
I did a WWM search and found somewhere that someone put 1.5” to 2” between
baffles. To fit the skimmer in the sump I need less than 3” between the
baffles, but the EV-180 can be put outside the sump if necessary. I have
space behind the sump, just not lengthwise.
<I'd place this IN the sump for sure>
5. Finally, the 10 gallon tank I have has a small chip in the glass (see
picture). It is a seashell shape with no cracks, but it is at the very
bottom of front panel on the edge. Under normal operation, it will be
half-full or so. Is it safe to use for this purpose, or should I pick up
another 10 gallon tank?
<I'd at least fill in the chipped area with Silastic. Won't help
strength-wise, but will save someone from a nasty cut>
Thank you SO MUCH for continually answering my questions. I don’t want to be
a pest, but I don’t really have many other people to ask for advice.
<We're happy to assist your efforts>
I live in a small South Alabama town, and I know of no one else here who is
into saltwater aquaria.
<Perhaps a posting on CraigsList? Starting a "Meet Up" group in your
area....? Easy, fun to do>
I have a friend who owns a LFS, but he is almost 2 hours away. I trust your
judgment. I have CMA and have read it twice. I read WWM FAQs constantly. Yet
often my questions are so specific I feel I need to consult the experts. I
just hope that it’s not TOO often.
<Welcome. Bob Fenner>
Re: Questions about Sumps and glass tank seams and chips
Thank you so much for your answers. I’ve never done a drilled tank with a sump
before so I have no practical experience at all—just what I’ve read or seen
looking under display tanks at LFS’s.
<Better, best to read... than trial and many errors>
So, I’m kind of flying blind—especially when it comes to what happens when the
power goes out. As the expression goes, that’s why I asked. You said some things
I thought you would say, and some things I didn’t expect. Either way I’m
grateful, but I also have some confusion, some clarifications, and some more
First of all, I’m abandoning the 10 gallon sump idea. I don’t want to cut it too
close, which is why I asked in the first place. It seemed too small to me.
However, one thing that you said that confused me is that the sump has to hold
all the water above the overflow of the main tank PLUS the refugium.
<It does mate... think... what happens when the power goes out, or the main/sump
The 20 gallon tank I was thinking of using as the DSB/refugium has a one inch
drain in the side near the top (a couple of inches down). I hadn’t anticipated a
lot of back flow from it because if the power head supplying it was three or
four turns per hour (60 to 80 gallons per hour in this case), wouldn’t that keep
the water level pretty close to the level of the drain, and thus not add much to
<.... you can calculate this for all surface areas... or just try it in real
I have tried to find plastic containers online, but the problem is the listed
dimensions on the website for them are for the outside rim, not the area of the
bottom (usually a good bit smaller). Whether I’m looking for a sump or a
refugium I need to know the area of the bottom so that I can know whether I’ll
have room for my pumps and skimmer (in the case of the sump) and so that I can
have as large of a DSB as I can (in the case of the refugium). I want to be able
to see the container first hand so that I can put a tape measure to it and know
what I’m dealing with.
<Meh! Life's a series of compromises... the slope isn't all that great on such
containers. Set the ten sideways on top of the right of the twenty...>
You suggested using the 20 gallon as the sump. The problem that I see with this
is the 1” drain hole. This drain hole will limit the amount of water it can hold
as a sump, unless I plug it. How would I go about plugging it?
<Silicone and a bit of plastic sheet or glass>
I have another option for the sump that I didn’t mention before. I have an old
acrylic wet/dry that is 23.5” X 10” X16” (16 gallons or so). Would it be big
enough to be a sump?
<Maybe... if very slow flow>
If I use this W/D, I can’t use the 20 Gallon for the DSB/refugium too, because
it is a half inch too long (Don’t you just hate it when that happens!). If I go
with this option, I’ll probably try to find the biggest plastic container that I
can fit into the space and use it for the DSB/refugium. Regarding that possible
1. Option 1 would be drilling the W/D and gravity feeding into the DSB/refugium
and then putting the return pump in the DSB/refugium container (basically a
straight line—W/D with Skimmer, gravity feeding into DSB/refugium container,
flowing through it to the return pump—walled off with baffles or similar). That
wouldn’t leave a lot of space for the DSB.
2. Option 2 would be drilling the plastic container and going with a power head
in the sump to pump water into the DSB/refugium and then gravity feeding it back
into the sump. Question/concern with this option is can you drill a plastic
container and use a bulkhead fitting?
<Most, yes. NEED two gaskets, Silastic and tightening the nut just so>
The slanted sides and softer material would seem to make this difficult. I
prefer option 2, but I wasn’t sure about putting a bulkhead in a plastic
<Have done so many times>
I’m also confused in regard to what you said about the Mag 7 pump. Reason being,
when I was considering buying the used pump I emailed you with some questions
about it, and you OK’d me using it in the way I described. Here is the text of
that email (I highlighted the pertinent part).
-------- Original Message --------
Sent: Saturday, February 14, 2015 5:45 PM
Subject: Re: Pondmaster Mag Drive Pump
Thank you for your answer. I picked up some good stainless screws for the pump,
but now I have another question about it. In the last email I told you that the
pump was a Pondmaster Mag Drive 700. I wasn't 100% certain of that since the
label on the side was missing. The guy told me it was a Mag 7, but I wanted to
be sure. So I did a couple of tests, and now I'm confused. In the first test I
used a two foot section of 3/4" (ID) PVC with an elbow and a 6 inch section of
Loc-line at the top. With this set up I filled a 5 gallon bucket in about 40
By my calculations this is around 450 GPH. I'm a little new to figuring out head
pressure, but after reading a lot of plumbing FAQ's on WWM I think I had around
3 feet of head on this set up. For the second test I used a five foot section of
3/4" (ID) PVC with an elbow at the top (no loc-line this time). With this set up
I filled up a 5 gallon bucket in about 51 seconds. By my calculations this is
around 350 GPH. I think this set up had about 6 feet of head pressure. I
looked up the head/GPH chart for the Pondmaster series on the internet. At 3
feet of head it a Pondmaster 700 should get 500 GPH, but I only got 450 GPH.
<Aye ya; you're a sharp one... this is close>
At 6 feet of head pressure, it should have get 400, but I got only 350 GPH. Yet,
it cannot be a Pondmaster 500. They are the same physical size (according to the
specs I looked up), but at 3 feet of head a 500 gets about 375, and at 6 feet of
head it gets about 175 GPH. It's got to be a 700.
So, here are my questions . . .
1. Am I figuring the head pressure right?
2. Is it just not running at optimum level? Could this be because of age?
(It's used, but I'm not sure for how long)
I got this pump to use with my Aqua C EV-180. If it's not putting out a full 700
GPH though, I don't want to use it for that. I might instead use it for my
return pump. Let me give you a few details on my planned set up in that regard.
I have a 75 gallon tank (factory drilled with 1" drain & 3/4" return &
overflow). I'm not going to drill additional holes. After a
lot of research of WWM plumbing FAQ's, I had decided to use both of these holes
for drains and limit my flow to between 300 and 350 GPH (and make up for the
rest of what I need through power heads). I haven't figured out all
the plumbing details yet, because I'm still in the planning stages and haven't
gotten my stand finished yet, but I know I'll have about 5 to 5 1/2 feet of
vertical distance from the sump to the top of the tank for the (over the side)
return. I'll have a little bit more head than that because I'll have to move to
a little the side to get out from under the tank to go over
the side for the return. I'm not sure how much additional head that will be. If
I use this pump, I know that at 6 feet of head it does around 350 GPH. If I use
much more than 6 feet of head through my eventual plumbing set up, then it will
(likely) get down to or below 300 GPH. Would that be enough flow through a
<< More than enough>>
Would I be better off with a more powerful pump (say a new Mag 7) and use a
valve to throttle it down if need be?
<I'd stick with/use what you have>
I'm not trying to put the cart before the horse. I'm trying to figure out if I
want the pump or not. The guy gave it to me to test, but I haven't paid for it
yet. I can give it back to him. I'd like to use it, because it means
considerable savings over new one, but if I can't use it for the skimmer or the
return, then I might as well give it back to him.
Sorry about the length of this email. Thanks so much for all you do for us
in this hobby.
<You're fine w/ this pump. Bob Fenner>
I had read the article on the 1” drain before (and all the FAQs)—after I bought
the tank, of course—and that’s why I had decided to use the return hole as an
additional drain and make sure that I had around 300 GPH after figuring out the
head pressure. I’m going to have a ball valve above the return pump anyway (to
make it easier to remove it if necessary) and I will test the flow before
filling the aquarium. IF I am too much over 300 then I will throttle it down a
little bit. Is that plan feasible, because I really don’t want to buy another
pump at this point?
<<Depends on the sump/.... you do NOT want the transit volume to OVERFLOW the
So, counting the text of the previous email pasted in, this may be the longest
email I have ever sent WWM. Is there a length record?
<<Oh, you're WAAAAY short of this>>
Thanks so much for your help, and for clearing up all my confusion. Y’all are
Thanks so much,
<Do you understand here Eddie? BobF>
Re: Questions about Sumps and glass tank seams and chips
I have come to understanding (I think) thanks to your patient help. I guess I’ll
never REALLY understand until I see it “in action”, but I’m a lot closer than I
The more water you push with the pump (the more GPH), the more water you will
have above the level of the drain (and standpipe), and all that’s got to go
somewhere if the pump stops working (power outage),
so you need a big enough sump to catch it all (or to use a much smaller pump or
bigger drain). And having a longer return line (which lowers the GPH due to the
head pressure) ALSO means more water in those lines that will back flow.
So, based on that realization here are the options going forward:
1. Plug and use the 20 gallon tank for the sump. Then I will find as large of a
plastic container as I can for the DSB/refugium and put a drain in it & feed it
with a powerhead as before.
Would this be a large enough sump if I keep my flow near 300 GPH?
<Mmm; maybe... again, have to actually try out...>
2. Try to find an even bigger tank or container to use as an “all-in-one”
sump/DSB/Refugium. It’s hard to find a plastic container that is long enough and
still narrow enough, but if I can find a 29 or 30 gallon tank for a reasonable
price, then I will get it and divide it up into chambers. I would lose the
advantage of the completely separate refugium this way, but I would gain a good
bit of extra space to “catch” the falling water. Would this be a better option
<IF the sump, fuge can't be easily fit in the stand as one piece, better to use
If I go with option 2, I can still plug and use the 20 gallon as a quarantine
tank—so it won’t be a wasted purchase. To plug the hole should the glass/plastic
go on the inside or outside (I would think inside)? How much bigger than the
hole should it be?
<The inside; about twice the size of the hole>
Thanks for being so patient with me (and for correcting me again if I still
<Clarity is pleasurable for all of us. Cheers, BobF>
Re: Questions about Sumps and glass tank seams and chips
I still have one little bit of confusion. Could you please clarify what you mean
in your answer regarding option two: “IF the sump, fuge can't be easily fit in
the stand as one piece, better to use two.”
<Fit one (the larger) in the stand first, the other (smaller) on top of the
Re: Questions about Sumps and glass tank seams and chips
By building a shelf for the smaller one to sit on or by putting it right on top
of the other one? It could hold the weight of the sand and the water?
<It should be; yes>
My stand’s front/center 2x4 is removable.
I can get a container or aquarium in there that is up to 39” X 16” or even
longer if it is less than 12” wide. So if I can fit a 29 or 30 gallon tank in
there, it would be better to go with one?
<The bigger the better. T'were it me/mine, I'd be making the sump... from
glass/Silastic or acrylic. Not hard to do; and w/ a bit of shopping, not
Crack in glass 1 month old saltwater tank
A crack is starting at the top of a 125 gallon saltwater tank.
You can feel the crack on the outside if the glass but not yet on the
<Mmm;;; it will be... with just a bit of a jarring>
It is full and has five large fish, live rock and some coral. I have had
the clown trigger and the red tooth trigger for over 12 years....second
tank. This tank is just one month old.
I cannot get a new tank to me for at least a week.
Is there anything I can put on the crack to stop it until I can get a
<Mmm; that I would do? Maybe silicone a flat piece of glass or plastic
over the cracked area... Lower the water level as much as you can...
have clean, soap/detergent containers on hand in case it gives>
Mysterious glass "issue" 2/17/16
Good morning, Bob,
I hope everything is well with everyone in WWM land! I write seeking an opinion
more experienced, educated than mine. I apologize in advance for the long winded
question, I just want you to have as much info as possible to provide the best
answer. I first wrote back in 2010 as I was setting this tank up. It’s a 75
gallon with starphire front and sides made by Glasscages. They drilled the holes
in the wrong locations and the silicone job was a mess but despite all the
horror stories I read (after I paid) the tank has been fine up until now. I
filled it and performed different tests on gear/temps for a few months.
Eventually, I ended up letting it go dry and the water mostly evaporated. Around
2013ish I cleaned everything out
and refilled. This time I ran saltwater through the system. I played with a few
things to eliminate microbubbles, did a few tests with the lights to gauge
temperature fluctuations, etc. After a few months of this, I then let the water
evaporate again, although with saltwater, this time the “sludge” was left on the
bottom and the sides. Quite the slippery buildup. Fast forward a couple years to
last month. I am finally ready to get my live rock shipped (pending your reply)
so I started cleaning everything up….AGAIN! For a couple of days I
filled the display with 6-8” of very hot water,
<Mmm; I would NOT do this. Too much chance of damaging the glass, seals>
wiped, siphoned and repeated. It was during this time that I noticed the “issue”
in the front pane. Granted, there is a .01%
chance this was there from the beginning, but highly unlikely as I would have
noticed it for sure. It appears to be a chip (?)
<I see this; on magnification the "chip" appears serrated... can you feel this
bit? Is it hard (like glass) or soft (like Silicone)?>
at the very bottom of the front pane, where the left side and it meet. Whatever
it is, it’s fully in the glass and can’t be felt.
<Oh! A chip...?>
Then, for lack of a better description, it looks like an “ant tunnel” going to
the right in an upward direction. This “ant tunnel” is about 2” or so in length
and is visible in the photos. Other than one spot about 1mm that I think I can
feel texture while scrapping with my fingernail, this tunnel cannot be felt from
either side of the front pane either. Photo “3033” shows the side of the front
pane and I have edited with a black line. The “chip” is right below this black
line. As seen in the bottom left corner of the full tank shot in photo “174201”
I have marked the “tunnel” with a crayon and filled the tank with water to see
if it got bigger/worse I hope I resized the images to an acceptable size for WWM
If they are too big or small, I can resend. It has been about a week since I
marked the tunnel and it hasn’t moved. I am going to put the powerheads in the
tank tonight, along with turning on the return pump, to see if movement or any
extra pressure caused by such, makes the issue any worse. With it being so low
on the tank, if it does malfunction it will be a total loss. So I definitely
wanted to get your expert opinion before I buy $700 worth of live rock and put
it in there. I wasn’t sure if being empty with temperature fluctuations in the
room could’ve exaggerated a blemish that I didn’t see originally or something
else could be the cause.
<Must be original... an unusual internal break in the glass>
Just at a loss really as to what could’ve happened. In your opinion, should I
scrap this tank and start over?
<Mmm: I would likely use the tank... as you state, it has been service-able till
now... the seams look okay, the frame...>
Proceed with rock?
Find a different addiction haha?
It goes without saying, but it would be heartbreaking to come this far and be so
ready, only to have to start over. As always, your opinion is very strongly
appreciated. The vast wealth of knowledge I have obtained through WWM and your
books is truly invaluable. Thank you sir!! I look forward to your reply.
<And you; Bob Fenner>
Tank Crack 8/31/15
I just bought a used tank and found a crack in it. The tank is over 200 gallons
and I was wondering what problems this would cause.
<Could fail catastrophically. Do NOT fill this tank>
The tank is 30" high and this crack is about a foot from the top of the tank. I
went through all of the crack FAQ's and I still wasn't sure.
Any help would be much appreciated. Picture attached.
<I'd be trying the strips of glass (1/4" will do, three, four inches wide) along
both sides of the chipped corner here... siliconed, meeting/overlapping outside.
re: Tank Crack 8/31/15
Oh, one more question. Do I have to remove the molding around the top and bottom
or can I place the strips of glass top to bottom between the molding?
<Were it me/mine, I'd leave the molding in place, do the latter. BobF>
Thank you again
re: Tank Crack 8/31/15
Wow, quick response. Thank you so much. I will definitely do that.
<Ah, good. BobF>
Chip in my new 140 gal talk
Thanks for having a website that address these types of issues.
I recently purchased a 140 gal aquarium and transported it to my home 200 miles
away (It was the exact tank that I was looking for.) The tank has polished and
beveled edges. After unpacking the Aquarium I noticed that it had a glob of
silicon (about the size of a dime) on one edge about 12 to 15 inches
from the bottom.
When I scrapped the silicon away with my razor blade a chip about the size of my
finger nail came up (very cleanly with no rough glass edges) The chip fits back
in the space almost perfectly (gluing back would be ease).
Attached are a few pictures of the damaged area.
It appears that I won't be able return the tank. (a) Do you think I'm over
concerned about the chip?
<I am too>
(b) Could this cause a complete tank failure after tank is filled?
<Possibly; if not then, potentially in time>
(c) Should I just get rid of the tank (Substantial loss) (d) Any other
<You could either commit this tank to other use, filling at most about half
way... Or do the "strip" glass appending gone over on WWM. The chip here is just
too deep, large and badly placed to allow me to be comfortable.
Siliconing a three inch, quarter inch/triple strength plate of glass over the
exposed height on the side... will likely be a lifetime repair... and not
noticeable if the tank is placed with its back along a wall>
I hoped that I would be finishing the thank set-up over the 4th of July weekend.
Not going to happen.
Thanks in advance for you assistance and speedy response.
<Again, welcome. Bob Fenner>
re: Chip in my new 140 gal talk 7/5/15
<Yes... but the usual spiels re ding dang reality!>
Thanks for you professional opinion.
I suspected that would be the answer.
Have a great day. And thanks for being there.
<Very glad to assist you. BobF>
Chip at the edge of braces
I thank you guys in advance for advice. I recently got a new aquarium,
but failed to notice a chip before setting up, as seen in pictures. I
believe it is not dangerous (since similar sized chips were dismissed in
previous FAQ posts), due to its position at the top and the fact that it
doesn't cut right through the glass.
However being right at the edge of the corner braces makes me wonder if
the pressure would cause the crack to propagate?
<Don't think so>
Should I be concerned? Did not seem to find a similar problem in my
<I'd just fill in the gap w/ Silastic to prevent cuts and not worry. Bob
Re: Chip at the edge of braces 3/7/15
Thanks for the confirmation! Your work is awesome.
<Certainly welcome. BobF.>
Urgent, tank chip 3/5/15
I took my 60 cube (24x24x24) down to clean it out and reset it up in my
room. When my brother and I placed it down on the ground, the corner
hit, and an 1/8 by 1/8 inch piece of glass chipped out.
Upon inspection, it is just in the front glass pane, almost like a
It is in corner of tank, with a mound of silicone inside the tank over
It does not come close to the joint, it's just in one window pane.
<I see this>
I filled it with water last night, and there were 0 leaks. Being the
glass is clear, you can see there are no fissures, cracks, spider webs
etc. it basically looks as if someone too a bevel, and removed an 1/8
piece of the glass, away from the joint.
I have read if it holds water your good, others have said any chip,
scratch or crack makes the tank useless.
Would really like your input.
I attached a photo. In the photo, you can see there is plenty of pane
left before it joins the next pane, or the joint.
<This looks like a "lucky" break; not likely to spread...
I would use this tank; but fill in the missing piece with Silicone; to
prevent fingers getting cut. Bob Fenner>
Re: Urgent, tank chip 3/5/15
Great news glad to hear it. I called the store I bought it from, and he said
throw it into dumpster. This is without even looking at it, and went on to
say a chip compromises the glass, and regardless of size of chip,
location, etc, you can't use it.
However, he is not an engineer, just an lfs owner who would love nothing
more than for me to buy another tank.
You say a lucky break..where do you draw the line from "unlucky" to
<Whether it can or needs to be repaired, or tossed>
Meaning if that chip was on the seam, or deeper, is that generally where it
Thanks again, and thanks in advance
question 2 chips on fish tank?
I found this on the right side of the 180 fish tank while i was cleaning
out the old silicone. I'm not sure if the chip was there before or not,
was under the silicone. The tank was running fine before i moved it,
it was caused during the move?
what should i do or will it be fine if it
can hold water for 48 hrs?
<Need to know where (how high up) this chip is... Have you read here:
Scroll down to the Aquarium Repairs tray; READ re Chips/Cracks>
Re: question 2 chips on fish tank?
<You've exceeded our file size limit by an order of magnitude>
Thanks for the help, i really appreciate it. The chip is on the very
bottom middle edge of the fish tank.
its around in the middle area on the right glass panel of the fish tank
I also noticed from top view of the chip there is a possible scratch or
crack? I also took some photos with a bright light inside the glass if
that helps. The glass is 1/2 inch thick.
<Keep reading. I wouldn't use this tank as an aquarium as is. BobF>
I would like you opinion about this chip on a used 140 Gal aquarium. I
noticed the shell shaped chip on a back corner once it was delivered to
my home :(
Fortunately its not very deep and doesn’t appear to have any starter
cracks radiating anywhere inside of it. Is there a such thing as
a clean chip?
<Cleaner... and less>
The chip is 1” wide, 2” tall, and the center sits about 7” from the top
of the aquarium on a 29” tall panel.
It doesn’t go wider than the silicon seam if you look at it straight on.
The depth of the chip at its deepest near the corner is about 1/8” or
tip of a finger, the glass is 1/2” thick.
<Aye ya; this chip is too large, deep to use the tank as it is filling
it all the way>
I was wondering if you can tell from these pics if I should do anything
to reinforce it as I’ve seen you recommend for other chips of similar
<Yes... I would apply three or four inch strips of quarter or 3/8" glass
along both edges of the corner where the chip is... Siliconing them
along the faces vertically>
Please give your opinion based on information provided.
Re: Chipped Corner
Thank you for your super quick assessment Bob!
I understand this as using two 29” tall x 4” wide x 3/8” thick glass strips
siliconed vertical to the back and side, correct?
I’m assuming this relieves the outward pressure away from the chip?
<Yes and yes>
Thanks for your help!!!
<Welcome again; BobF>
Re: Chipped Corner
Thank you, I’ll try this and keep my fingers crossed, the chip honestly
doesn’t look that bad/deep, but its large surface area is the issue I guess.
Does it matter which corner overlaps the other as far as strength goes, or
should I just match the corners of the aquarium?
<I'd cover over the chipped edge, meeting up level w/ the piece on the other
Re: Chipped Corner
Will do, thank you Bob for all the help!
Cracked aquarium corner
Good afternoon. I came across WWM as I was researching how to address a
crack on the corner of my 90 gallon. I read through your other posts and
it appears that no one has inquired about my particular situation yet. I
have had the tank for 14 months and noticed the crack about 6 months
ago. As I have a reef tank, I really don't want to tear it down so I
I'd observe first. The crack runs only through the front plate. When
viewed from the front, it is 1/8" wide and when viewed from the side, it
is 1/16" wide. If you viewed top down, it would be triangular. If I
measure the height, it is 1.5 inches long assuming that it starts from
the base hidden by the trim. It appears to be very slowing
moving upwards. So, as the crack
is not moving in towards the tank, I was thinking about removing that
piece (maybe with a Dremel saw?)
<NO! Don't do this... glass... being a super-cooled liquid... can be
ground down, but this will NOT improve the structural strength; and very
likely dis-improve it>
so that it doesn't keep moving up. What are your thoughts? I have
attached a few pics. Thank you
<Well; as the break/crack is moving; I would decommission this
tank; sell it to someone for partial-fill use... for aquatic
turtles, a paludarium perhaps... or dry use. Otherwise, you could
Silicone on supportive strips as gone over on WWM along the
corners/edges of the broken pane. I would NOT leave this tank up and
running as it is... there IS a very real chance of sudden failure
here... disastrous for your livestock, floor and should anyone be near
when it catastrophically fails. Bob Fenner>
Re: Cracked aquarium corner
Thank you for your advice! I had hoped it was as simple as removing
<Removing the one panel.... really more work than it's worth. What is your
I have contacted the vendor for a replacement. Not looking moving the fish
and coral! Thanks again.
<Simple to do... See the "moving plans" on WWM... get the tools, mat.s
together... a friend or two; do it systematically and it's no big deal. The
peace of mind.... well worth it. BobF>
I purchased a 42 gallon bow front tank from Craig's list. I discovered
when I got it home that there is a chip inside the seams as if it was
bumped. It's smooth on the outside and inside and it does not leak. I'm
worried about making this into my larger salt water aquarium. Do you
think I need to make repairs such as this. Or am I being paranoid? I've
some photos. Thanks for your help on repairing or leaving this alone :)
<Only one pic came through, twice... where is this chip at on the
side... IF near the top few inches likely it will be fine... if lower
down on the side, I would at least effect a two inch strip of glass down
both sides... Siliconing the strips in.
Thanks for your help.
Yet another chip question
I'm sorry to bother you with another question about chips, but it seems
every inquiry is slightly different from mine. We bought a used 40
gallon breeder, and neglected to set it up for a few weeks. When I
finally cleaned it, I noticed a shell- shaped chip on one corner, about
2.5" down from the top. A pair of freshwater angels is going into it, so
I need to be able to fill it completely. Some silicone was also flaking
off as I cleaned. Is this tank okay or should I get rid of it?
<Well, the chipping looks okay (near the top and not too likely to
spread)... do fill the area in w/ Silicone to prevent cutting your hands
and fingers. The Silicone flaking off? I see that the bonds look okay on
the glass itself... IF this is the case I think you're fine here as
well. I would try this tank out as is at this point, rather than cutting
out and replacing the internal/corner seals. Bob Fenner>
Chipped edge 10/31/14
Hi guys I found your post and hope you can help me! I bought a used 110
xh reef tank and have it in my office. It looks like someone bumped it
and chipped a piece off of the corner about the length of a nickel and
as thick as a dime. Do you think this is still a usable tank? Thanks!!
<From the size, shape and position (nearer the top), I think you'll be
okay with this chip. I would fill the gap in with Silastic/Silicone
Rubber, to save yourself from easily cutting your hands, arms on the
Chip in tank 10/8/14
Hello, kind sirs. I've got a standard 55. Upon
inspection I noticed a small chip roughly 1/16", maybe 3/32"
long and wide (circular-esque) and MAYBE 1/16" deep at the most. Its
roughly 3" off center and almost exactly halfway between top and bottom.
The glass itself is 1/4" thick.
Safe to use in your opinion? Any answers would be greatly appreciated.
<This small chip should not be a problem>
Thanking you in advance...
A concerned father of 2.
<Cheers, Bob Fenner>
Re: Chip in tank 10/8/14
Thank you for your timely response, sir. My daughters, 5 and 4, tell me to
tell you "Thanks you for fixing our fish house."
<Welcome. Bob Fenner>
Movers crunched the end of my 90 gal tank about half way down
Hi!! Movers crunched the end of my 90 gal tank about half way down.
Holds water, no leaks. Think its ok, or should I try to reinforce?
Thank you in advance
<I would Silicone on a glass strip about four inches wide on the chipped
face, matching the corner. See WWM re.
Re: Movers crunched the end of my 90 gal tank about half way down
On the inside or outside? Thank you for the quick response
<Out. Read where you've been referred. B>
Chipped rimless new tank 100g cube
Hi I'm concerned about a chip in my new tank I've attached pics the chip
is not on the outside... chip is on the side
glass at the bottom of the tank in the seam
between the side and the bottoms glass only goes threw half the
thickness of the glass on the seam... what should I do if
anything? Thank u guys...
<Mmm; I think you might be lucky here... the scallop type breaks can be
forgiving. IF the tank is empty and dry currently I would fill in the
chipped area with Aquarium Silastic/Silicone (more for preventing cuts
to human hands than structural repair)>
Also what do I put under the tank between the glass and wood before
filling the tank I heard foam... If so how
thick? Can I use a rubber pad?
<A half inch cut piece of either is what I'd use; assuring the stand
surface is strong, linear and planar as well of course.
Re: Chipped rimless new tank 100g cube
The crack is in between the glass on the bottom it is not in a place where
it could be touched...
I was just worried about the silicone seam.. that is
where the crack is and it has broken the seam half way threw... should I
attempt to get broken glass out before recaulking?
<No; I would not>
Or should I just put a
thin layer over the bottom to fill it in.... ty for your response and how
quick u were
<Welcome... and surprisingly, am out dive/visiting in Bali currently.
re: Chipped rimless new tank 100g cube
Wow that's great to hear takes a lot of weight off my shoulders knowing it
should be ok... wow I wish I was diving in Bali that sounds awesome. ..
Enjoy your time there thanks again for your quick response
<Certainly welcome. Bob Fenner>