[Stan510]

As Acrylic gets years old,fine scratches build up- as we all know. So,I read two years ago that toothpaste can remove fine scratches. Now,I don't remember if that was for just the outside of the aquariums..but I wanted something for the inside of an aquarium with fish and plants that are going full gun.
So I tried it one day when I drained the tank low..maybe 65% ot the water drained out. I put the paste on a cotton cloth and went at it like I was polishing the car by hand. Let me tell you,it not only removes fine scratches,it removes the hardest algaes there are. All,non toxic 100%.
Now,one try improves..but make it almost regular and see the old tank look pretty good.
Just to finish,I think I'm going to try toothpastes with small amounts of hydrogen peroxide in them. Wouldn't that be a killer if it made the glass clear AND KILLED off BBA,BGA and the rest? HP in tiny doses..could work. Or not.
Now,if you have an old empty tank to renovate then for sure use electric hand orbital sander and commercial acrylic polishes. No argument that's the best way.
But for maintenance..

 

[Deanna]

Yes: toothpaste can be used as a mild polish for acrylic. Toothpaste contains very mild abrasive additives that will remove some of the acrylic surface. This works for very mild scratches that appear almost more as a haze and the water can then fill-in these light scratches, somewhat, to mask the haze. Products from Novus are probably better than using toothpaste that may have varying quantities and types of abrasives and chemicals. For larger scratches, a very fine sandpaper can be used.

Step-by-step instructions can be found all over the Internet. However, Novus has a long-standing product line that is dedicated to acrylic and are highly reputable in the acrylic world.

 

[Stan510]

Novus is for exterior. My brainidea-ha- is for old tanks in use and yes,getting a milky haze from micro sized scratches. I've been using toothpaste on the inside and various Meguiar and Novus polishes and cleaners for the outside. Toothpaste is when you draw the tank low..spread on cloth,and polish away the INSIDE of the tank..watch as hard smear gray algae is removed ( that stuff you can actually FEEL as rough and is very hard to remove any other way) when exposed to air. I have even reached down lower than water level..it just takes more paste as it dissolves faster.
No problems with fish or plants. I do wipe away as much as I can I should have said with paper towels..THEN I refill the tank.
I have never see any fish have a bad reaction to the paste..and just as you polish anything,you don't want to use a thick glob..just a nice thin spread and then polish away.

 

[Deanna]

The algae issue is a separate issue, but I would expect that any mild abrasive would work well to remove algae, and toothpaste generally contains such mild abrasives. I would probably be a little concerned, though, about using it too often as it could cause a haze to develop.

Novus can be used on the interior as long as it is buffed completely (I think they are silicone based). If you have good success with your toothpaste, it might be be a good idea to post the brand and version since each brand is going to be a little different, chemically.

 

[Dreya]

I wonder if toothpaste would work on that annoying hard water line

 

[Stan510]

Sure it would. Leaves the room minty fresh too.
You would only use the toothpaste as needed. If it looks as good as it gets,then stop. But when hard algae builds it does a great job on it. I've used Colgate- Sensodyne. I think the Sensodyne actually does a slightly better job funny as that seems.
My aquarium is so old- over 40 years now- It would never look perfect again but the acrylic looks better than it has in ages- at least the front panel. No need for the rest of the interior to get the paste. I only look at the front and the sides are not algae plagued like the bright middle of the aquarium. The back panel I just use scrubbers for algae. For some reason the gray hard slime just settles on the front panel.
Once again,if you go big tank..Acrylic is near forever. No way a glass 240 gallon goes 40 years without a problem. Not with as many taking downs,resets and stored standing on its end *true) and crooked stands. Any glass tanks would have broken long ago.

 

[Deanna]

Certainly try it, but I think you will be there a very long time with little progress. I’ve had calcium deposits in the past (water’s too soft now) and it resists my Brillo pads and other aggressive efforts, without a chemical involved …on glass (don’t recall if I had Ca deposits on an acrylic tank I had). However, an acrylic surface is different from a glass surface. It may be that the Ca is not bound quite as well to acrylic. Please let us know how it works out.

If it doesn’t work, you might try lowering the water level below the Ca line and scrub it with micro-fiber cloth and distilled white vinegar. Just be careful that you don’t add so much vinegar that your tanks’ pH drops too much. This mild acid should not attack the acrylic, chemically.