Perhaps the kit came with a rubber ring and a plastic ring??? I could not find a good pictorial for an example, so what i state is subject to correction. My guess is that IF you have a rubber washer, the rubber washer ("o-ring") goes inside the tank - yes? Then the plastic washer goes on the outside. The rubber ring on the inside provides the seal and the plastic ring provides slip for the locking nut to turn. anybody else?

I have some old ones back behind the shed. Its late, but I'll check it tomorrow.
Can you turn the square piece too?
If you don't need to drain it through the drain, you could try caulking around the drain. Did you use plumbers tape on it?
Some years, mine would leak a bit, until it had a few days to build up some dirt in it, and the dirt would seal it.
Are you sure its not cracked anywhere? I had some cracks that would hold until it got half full, and then the pressure would make it leak.
I really don't think you need to buy a new stocktank.
Let me look at the drain fixture tomorrow, and then we'll talk some more about options!

Did you clean the plug and socket really well? Once that is done a double thick layer of Teflon tape makes the seal good for my tank. One thing I found that is important is the tank must be level otherwise the tank distorts and it is almost impossible to get a good seal. I mention that because you say it doesn't leak until the tank is partly filled. Before the water level reaches a certain point the weight might not be enough to distort the tank so until the tank does distort the seal would be tight. You might have to put in some concrete blocks to keep it level. Sandy

Jenny,
I have a tank that leaked, too - no matter what I did. I finally got out my trusty hot glue gun (a girl's friend!) and put glue on, between the tank and the inside gasket, just before I screwed it together. It took 2 of us a couple tries, to get it on and together before the glue got too hard - you have to work fast. It hasn't leaked since (4 years) and I am not taking it apart!!!
sam

Hi again Jenny,
I took a look at the ones behind the shed, and I didn't want to mess with the drain plug too much........but now I think I remember that you have to also tighten the bigger flat round plate behind the square screw plug. I believe they both need to be tightened. So do that, but first put a ton of the white plummers tape on the screw first. And tighten it with something like channel locks.
Once I have that thing tightened and it doesn't leak, I don't mess with it. I drain the stocktank with a big aquarium gravel vacuum thing, and then when the water is low, I just tip the stocktank over to get the rest out.
Overuse of the drainplug will just cause problems.

Jenny have you tried Oring grease? I had a leak in my biofalls bulkhead and ended up having to use Oring grease on it and the drips stopped right away. Take your orings off and lube them up and put them back together. Have enough lube on there that when you tighten it down it oozes out. That worked for my leak anyways.

Troy

Thanks everyone for all your ideas. I was so frustrated yesterday that I turned the skippy on and let it drip. I placed a piece of rubber liner under it so it can drain away from the filter.

Thomba:

Kit came with 2 rubber rings and one plastic ring. One rubber ring goes on the outside of the tank the other inside. Then the plastic one goes over the rubber one on the outside of the tank. It still leaks.

Catherine:

No I didn't try teflon or plumbers tape. Good idea though. I can't turn the square inside the tank because it's too close to the bottom of the tank. The corner catches as I try to turn it. My channel locks barely fit the plastic ring. Maybe I need bigger ones.

Sandy:

When I installed the skippy I didn't pour a footer or place it on cement blocks. It was level when I first set it up but I know it's not level now due to the ground settling. I raised my skimmer on Saturday and figured I would save the skippy remodel till next year. I thought the same thing because it doesn't leak till it gets a certain level. The area around the plug was clean but it was also wet. We were trying to do this in the pouring rain. Maybe it has to be completely dry to get a good seal. I already turned off and drained the skippy twice. This is getting very frustrating.

Troy:

Never head of o-ring grease. Do they sell it at Home Depot or Lowe's? Would it be in the plumbing section?

Sam:

Glue is an idea, but I think I'll use it as a last resort. Of course I could made a sandwich of hot glue, teflon tape and o-ring grease. I do have acrylic seal. Maybe I'll try some of that. It's supposed to rain all week so I probably won't be able to do anything till next weekend.

At this point I am willing to try anything.

Jenny

Jenny, It is easy enough to see if the tank is level. Just use a level. I can open the plug with my achy hands and put it back with no leaks at all.
O-ring grease is also called Lithium grease. Sandy

Jenny,
After looking at my tank, I realized that you can't turn the inside part, but I think you can tighten the outside plastic ring. I think you can tighten both......the outside ring and the plug. I had a leak once and realized that I needed to tighten the outside plastic ring to stop it.

It was nice today so I drained the skippy again. I put silicone seal around the o-rings, the square threaded thing that the plug goes in, and the plastic o-ring. I tightened it with huge vice grip pliers I stopped at Home Depot and bought tonight. I am going to let it dry till tomorrow night and keep my fingers crossed.

Sandy you were right. It wasn't level. I was able to level it by putting a flat board under it till next year. Will keep you all posted when I fill it up tomorrow.

Jenny

I use my stock tank for a pond. The plug leaked so I stuffed a foam sponge all the way into the hole til I couldn't see it anymore and tightened the plug as tight as I could. It stopped the leak. For added protection, I pushed sand in and around the hole.

I have 4 qpp gallon and 1 300 gallon, and they allnleak. is rubbermaid gonna do anyth aboutnitabout it??

I have 5 rubber maid tanks-they all leak.

I haven't had many un-fixable drain plug leak problems in all my Rubbermaid stock tanks, but I've had 2 300 gallon tanks crack on the side......right around the same place. My tanks sit on the ground and they are never absolutely perfectly level, but not bad. I tried several years ago to fix the one crack, but it didn't work. Now I have another one doing the same thing. I think I have to try with more "stuff" to fix it.....cause it's such a waste to get rid of these (recycle), just because of one little problem. I'm sure if we were "fix-it" type people here , it wouldn't be a problem.

Back to the drain plug leaking.......I've found that if you just let it leak a little while, debris builds up around it and stops the leak. But I usually have plants in mine....which can create debris, but ones that are drinking tanks for livestock/deer, wouldn't get very dirty.