What are you dripping that long? I think the volume of water in the bucket will make a difference as will how much higher the bucket is over what you are dripping it into.....
I bought a pack of adjustable airline valves (99p) & found adjusting one of those a lot reliable than knots
30gal tank, 20kgs Fiji + 4kgs Madagascan LR, bare bottom, 2 x Maxijets 900, AquaC Remora skimmer, 10W D&D UV using a spraybar on surface for return,Maxijet 600 + spraybar behind LR, Ecco 2234 running RowaPhos/GAC, 150w visitherm.
Custom Built lid; 2 x T5 megatwin (4x39W Aquablue+); 4 moonlights.
IKS with temp & PH probes, controlling lights,heat & cooling fans.
Percula Clown; Banggai Cardinal; Firefish; Mandarin
2 Cleaner Shrimps; 3 Peppermint Shrimps; 1 Blood Shrimp
1 Large Feather Duster; 1 Hard Tube Coco Worm; Yellow Cucumber.
6 Red Legged Hermits; 1 Green Emerald Crab; 16 Dwarf Blue Leg Hermits; 3 Zebra Hermits; 3 Popsock Hermits
22 Turbo/Astrae Snails; 20 IO Snails