Sump Question

racefan

New member
I have a 20L I'm going to make into a sump. What I'm wondering is since it's glass do I need to use glass for baffles or will acrylic work? Also I seemed to remember reading once not to use Plexiglas is that correct? Oh another, What thickness? Thanks.
 
I am actually in the middle of making one right now for my 40 breeder -- I am using acrylic (( 1/4 inch, 1/8 inch bows too much )) baffles, and using silicone to hold them in place. This is the 4th sump I have built, and the rest were made the same way -- the oldest being about 8 years old now, and the baffles are still in place.
 
Planning on doing the same thing. I was thinking acrylic since I'm not concerned about it scratching in the sump.
 
Not sure if its true or not but I have heard silcone doen't bond well to the plexiglass so baffles in your sump should be glass is your sump is glass
 
Not sure if its true or not but I have heard silcone doen't bond well to the plexiglass so baffles in your sump should be glass is your sump is glass

Been working for me for 8+ years, so for a sump it works great.

I am actually in the middle of making one right now for my 40 breeder -- I am using acrylic (( 1/4 inch, 1/8 inch bows too much )) baffles, and using silicone to hold them in place. This is the 4th sump I have built, and the rest were made the same way -- the oldest being about 8 years old now, and the baffles are still in place.
 
Good info as one learns something new everyday. If I would of known that before I would of used the acrylic I had in my garage instead of buying glass baffles.
 
my most recent i used glass. I have used acrylic in the past with success and failure. In my opinion use glass. You should be able to buy cut and polished baffles from a local glass shop for around the same price as acrylic. Plus you will have no questions that the bond will work. I used rtv108 as the silicone. Made mine out of a old 40 gallon breeder. I can pick the tank up by the baffles. Would never try to do this with acrylic baffles. Granted why would you want to, but that is the difference in the bonds.
 
Whatever you use, make sure to get the bottom corners cut/rounded off -- most (( if not all )) standard tanks will have a silicone bead along the bottom edges; if you leave the corners normal it, most likely, not fit snugly at the bottom.

Need to upload better pictures, but this is from my old one -- to see what I am talking about;

P5150022.jpg
 
Whatever you use, make sure to get the bottom corners cut/rounded off -- most (( if not all )) standard tanks will have a silicone bead along the bottom edges; if you leave the corners normal it, most likely, not fit snugly at the bottom.

Need to upload better pictures, but this is from my old one -- to see what I am talking about;

P5150022.jpg

When I glued in my glass baffles I wish the bottoom edges were cut like that. Makes life easier.
 
I used acrylic baffles with my 30L glass sump. Make sure to cut the baffles a little smaller. I then lay a thin layer of silicone between glass and acrylic. So far I have not have any problem with the sump.
 
i am actually in the middle of making one right now for my 40 breeder -- i am using acrylic

+1


not sure if its true or not but i have heard silcone doen't bond well to the plexiglass so baffles in your sump should be glass is your sump is glass


-1


well im no expert.i bult my sump from a 29 glass tank with acrylic baffles and a built in refuge tank.and all i used was silicone and acrylic.the hard part for me was the refuge cause its like a mini tank in the middle.the water comes threw the first stage hits the live rock goes threw the baffles down a narrow path near the refuge(the water never goes in the refug cause its inclosed)hits the 3rd stage a skimmer then my return pump.as for my refuge my water from my main tank goes down the pipe hits a t (a small amount of water flows into my refuge.my refuge has a 7 inch sand bed and cheato. On one of the walls i cut a hole and glued a 1 inch pvc pipe to a elbow to a 1 inch pipe that goes up (-1 inch) to top of refuge.the water flows into refuge fills up to top hits the top of pvc and goes into the tubing flowing into sump water.i know it sounds complicated but its awesome.pm me i can show you pics.


Also in the middle of design i had to remove one baffle that was already siliconed.just me yanking on the baffle i was able to pickup the intire tank just me grabiing the siliconed baffle.tuff stuff.

Wait 48 hours before filling with water.let silicone completly dry.
 
ALSO I USED THE SAME SILICONE AS Toddrtrex.YOU CAN SEE IN HIS PIC.THE ONLY THING I DID DIFFERANT WAS THAT I WASNT BEING CHEAP ON ADDING SILICONE.I ADDED A LARGE BEAD AND SMOOTHED IT OUT WITH A FINGER.I WANTED TO BE SURE THAT IT WOULD LAST AND NOT HAVE ANY LEAKS.ONCE I KNEW THE SILICONE WAS CURED I FILLED THE REFUGE(UP TO THE TOP NEAR PVC) AND THE FIRST CHAMBER(UP TO TOP OF BAFFLE) W/ WATER AND WAITED 24 HOURS.(TO BE SURE IT WOULD HOLD AND NO LEAKS.
 
Silicone doesn't bond to acrylic as well as glass, but when you're building a sump you'll have water on each side of the baffle putting force on it so it doesn't need to hold all the weight in on one side.

I've built them both ways and you'll be fine with acrylic, especially in a tank with that low of volume.

Also look for Silicone I when you do it. It looks like the one in Todd's picture is Silicone II which has mold inhibitors in it 95% of the time (not sure if that particular one does)..... Make sure you don't get any mold inhibitor caulk.. If you go to Lowes or HD for it, it's in the gray and blue tubes....

GE-Silicone-I-reef-safe.jpg
 
same issue

same issue

I have researched this and can't come up with clear answers. Amazon does have weldon 16 and it is cheap to ship by ground. That would work for acrylic baffles in an acrylic tank. For acrylic baffles in glass (ore vice versa), I understand silicon wont stick well. I purchased GE 100% silicone sealant at HD and Lowes "for plastic sheets and other plastics". But I can't get rock solid data on its safety in a reef tank. I'm not going to risk it.
 
+1 on the badazztealcobra. good eye didnt see the II. NEEDS TO BE GE SILICONE 1 ALSO CLEAR.or you could but the aquarium at your local fish store but my petco costed 10 bucks and had only half as my as the ge tube.
 
Silicone will stick to acrylic, but it will not form a permanent water proof seal. Try to pull a tank apart and you will understand the difference. To make sure you do get a good bond make sure that the glass is cleaned using acetone and clean the acrylic with soap and water. You don't want ANY oils on the pieces or it will not bond.

The GE silicone is perfectly reef/fish safe as long as it DOES NOT contain the anti-mildew ingrediant (I think the GE silicone II does).

Use 1/4". Even though 1/8" will work, as stated the 1/4 is stronger and won't bow under the water pressure against the face.

I built my sump recently and used the Weld-On products. I used the #3 and the #16. The 3 is like water and the 16 is like syrup. I ordered from TAP plastics. Got the 3, 16, two applicator bottles and two tips for $20 or so shipped. Very cheap.

HTH and good luck.
 
I say glass,,I made mine with acrylic and the bond just is not the same as my old sump made with glass. It does not cost any more so why not do it once and only once?
 
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