cornclose
Fish Fanatic
Silicon sealant is no good in the long, medium or even short term. The best way is to use some air line 'through' connectors (inline connectors) as these usually have a collar in the middle. Drill the correctly sized holes in your bottle lids for these through connectors to push into (right up to their collar), then use epoxy resin on the inside of the bottle lids to seal them. This will dry solid and I guarantee you will not leak if done properly (clean/dry/residue free before applying the resin...). Make sure you don't get the resin on the bottle lid threads of course!
I've been using this system now with the same bottles for nearly two years (two 2-litre bottles with a 500ml bubble count bottle) and have never had a single leak anywhere in the system. There's no sign of needing to replace anything either.
Mixture I use lasts 3-4 weeks, so I stagger the two bottles about 2 weeks apart so that I always have CO2. Each bottle has its own non-return valve so I can change one and clean/refill with new mixture without losing pressure from the other bottle.
I feed the CO2 up via a third non-return valve into a small powerhead. This chops and diffuses the bubbles and allows them to dissolve into the water with good effect. The powerhead is time controlled so it goes off at night, allowing the plants to degas their CO2 keeping the pH very stable in the tank. Of course the bottles still produce CO2 at night, but the bubbles just exit thought the powerhead and float to the surface, so they don't dissolve into the water.
I've been using this system now with the same bottles for nearly two years (two 2-litre bottles with a 500ml bubble count bottle) and have never had a single leak anywhere in the system. There's no sign of needing to replace anything either.
Mixture I use lasts 3-4 weeks, so I stagger the two bottles about 2 weeks apart so that I always have CO2. Each bottle has its own non-return valve so I can change one and clean/refill with new mixture without losing pressure from the other bottle.
I feed the CO2 up via a third non-return valve into a small powerhead. This chops and diffuses the bubbles and allows them to dissolve into the water with good effect. The powerhead is time controlled so it goes off at night, allowing the plants to degas their CO2 keeping the pH very stable in the tank. Of course the bottles still produce CO2 at night, but the bubbles just exit thought the powerhead and float to the surface, so they don't dissolve into the water.
