If the sink is lower than the tank, the siphon effect should be stronger than if the sink was higher. Can you describe how you are setting up the siphon, and what the differences are in height.
Many of us use the python/aqueon type systems, but without hooking up to the sink for draining, then connecting to sink when filling. I create a suction by putting one end in the tank, and sucking on other end of hose, then placing it either on ground outside or so that it flows into the tub. This provides plenty of siphon to remove water.
I also just use gravity for draining and use the faucet for refilling.
Here is what you want to check on though:
1. Make sure the hose is not kinked. If there is a kink in the hose it will restrict water flow. To remove kinks, soak the hose in hot water to soften it and then massage the kink out.
2. If your household water pressure is low the venturi effect will be weak or nonexistent. This is common in homes on wells or in some older apartments. Better to let gravity work your drain than a weak venturi.
3. Make sure your valves are open and that they are not clogged with debris (gravel, snail shells, plants, etc...)
I apologize for the response, I just measure the height of the sink 32 inches high and the tank 31 inches( so I was incorrect). also the sink is about 26 feet away from the tank and I am using a 50 hose, which I need to cut.
Everything is clean with no clogs and I checked the hose for kinks and didn't find any(good idea about soaking the hose, I'm certain I will need to use that method in the future. thank you) and my house is city water so I think the water pressure should be good.
I have a similar situation as you. Are you near a window? I ended up siphoning out a window with the python, it gets great draw with the other end all the way on the ground. Then I just pull it in and attach to the sink to refill.
Yes, a pump like that will work. FWIW, even though the python/aqueon systems come with a gravel vac tube, I prefer to keep the task of water changes separate from gravel vacuuming, meaning I use a traditional siphon and bucket to clean gravel and just the hose for the bulk of the water change. With 1 or 2 bucketfuls, I can clean the gravel, and not worry about the siphon or hose for the majority of the water.
Since changing to sand, the need to vacuum is significantly lower than when the tanks used to have gravel substrate.
Keep in mind that any inline pump will clog with the debris you are sucking out. Snail shells, gravel, plant material can all make an inline pump pretty time consuming to constantly break down and clean.
You can also drain into your toilet. Just use the seat to hold the tube in place.
The problem is really related to the lack of a height differential. You are essentially trying to siphon uphill (physically impossible). So all you have pulling the water is the venturi in the faucet. Which will do it, but very slowly.
Trying to find a solution that allows gravity to help you is the best.
Hi nodima - I think I'm going to do the same as you, use between 1 and 2 buckets( what ever it takes) to do a deep clean of the gravel and then siphon through the hose for the remaining bulk water removal.
Andy- agreed, my only solution is allowing gravity to assist or its going to be a uphill battle.