I use that hose kit that hooks to the tap... it siphons out the water and then I put it back in again.
I add the water conditioner to the tank one i have replaced the 30% water i removed.
What would you suggest ?
Hmm... Well I'm still kind of new, but I think this method you're using is probably causing at least some of your trouble, if not all of it. Someone else can correct me if I'm wrong, but this is what I have read.
You are supposed to put the conditioner into the new water BEFORE you put it in the tank, then give it maybe 5 minutes to work.
As you know, chlorine kills living things in the water, including the beneficial bacteria you are trying to build up, and sometimes your fish too. What is supposed to happen when you put water conditioner into the new water is it changes the chlorine and chloramines into some other inactive form that doesn't kill things.
You don't ever want to add tap water straight to the tank, because the chlorine that is in the tap water can immediately start sterilizing everything it touches in the tank, killing the beneficial bacteria you wanted to grow. I think the way you've been doing it has been killing off some of the beneficial bacteria each water change, which is slowing down or stopping your cycle from finishing.
Also, if you measured the amount of water conditioner to use based on how much water you were replacing, then this amount is supposed to be added only to the new water, not to the whole tank, if that makes sense. But I don't know if you have been using the amount of water conditioner based on your tank's total water volume, or based on just how much water you were replacing.
Bottom line:
Here is what I would suggest. You said you use Big Al's water conditioner. Does it say it removes chlorine and chloramines? If so, good. If not, you need to buy something that removes chlorine and chloramines. I would highly suggest Prime but you can use others like API Stresscoat. You also said you use Big Al's Bio Support, that should be fine if you use it after the chlorine is gone.
Try this. Stop adding tap water directly to the tank. Instead, after you have siphoned off and removed as much water as you want to from the aquarium, remove the hose from the aquarium, and use it to fill some buckets with as much water as you need to put in the tank (make sure they are clean!). Now measure and apply some water conditioner to that water in the buckets. This should be a water conditioner that removes chlorine and chloramines! Mix the conditioner into the bucket and give it at least 5 minutes to act. Remember to use the amount of conditioner specified for the water in the buckets only. You are only conditioning and treating the water in the buckets, not the whole tank.
AFTER that, there should no longer be active chlorine in the water. Now add the Big Al's Bio Support, once again using only the amount specified for the amount of water in the buckets.
After that, now the water in the buckets is all conditioned and free of chlorine, now it's safe to put it in the aquarium. Carefully pour the water from the buckets into the aquarium, or use cups or bowls to scoop it in a little at a time. Or if you want to get really fancy you can put the bucket up higher than the tank and use a tube to siphon water from the bucket into the tank.
I think if you switch to this method, you'll get better results.