Q Dear Dave, The lake I spend most of my time on is about 60 acres and have to put casts out to about 150yrds so I get a few of what I call spin Knots where the line wraps round itself to form a small tangle. This happens with all brands of line I have used. 
A Loose coils when casting at long range are down to one thing only, inconsistent tension when spooling up or retrieving. When spooling on new line the tension between your fingers should be set at a suitable level, the pressure being placed on the mono should be consistent all the way through. That way all the coils end up having the same degree of tension like peas in a pod sitting snugly on the spool. 
Loose coils that occur when casting are a sure sign that at one point the line has been wound on with an unequal degree of tension. Varying tension not only occurs when winding brand new line on but also can be induced whilst retrieving. You can spool new line on in a perfect manner and when you cast it will behave spot on without loops. But when retrieving if the tension is not constant, or it is slightly haphazard, the following cast will often produce a loop. 
Loops are mini birds nest, they are created by the manner which line is wound onto the reel. The correct amount of tension has momentarily slackened at some point. The coils wound on with slightly lesser tension sit marginally looser on the spool. You cannot spot them with the naked eye. In turn they are then covered with further coils containing the correct degree of tension. 
As the cast is made the line departs from the spool tripping over the rim in a constant manner. As the line level becomes lower each departing coil comes up against slowly increasing resistance and the line speed gradually reduces. When it gets to the turn of the slightly looser coils to trip off the resistance is dramatically reduced and they peel off faster, albeit briefly. The sudden change in speed allows the slacker coils to accelerate and surge forward, they quickly catch up and catch up with the slower moving coils ahead! 
That is how a mini birds nest or wind loop/knot occurs. It is the same thing that happens using an overfilled spool, you never suffer with birds nest on an under filled spool. It can take as little as two turns of the bale arm with incorrect tension to cause a rogue coil. 
The key to trouble free distance casting is developing a perfect line lay with the emphasis on equal tension throughout. The longer the distance the more crucial the line lay becomes. When retrieving it is always advisable to keep the speed constant. High speed retrieving often is the cause of varying tension as the spool builds up. You will achieve far more control and equal tension by winding in at a slower and steady pace. No big loss, all it means is that your rig will arrive a few seconds later. 
The degree of tension between too tight and too slack is very slight, it really is only marginal. Watch the professional tournament casters in action, fixed spool or multipliers it makes no difference, they take an eternity to wind in. The longer the distance you are casting the more time you should spend on the retrieve in order to get 'that' perfect line lay for the next chuck. When you are casting a shorter distance no loops appear, because it’s only a lob. However when you have to use full power and compress the rod to its maximum the line leaves the spool in a blur, if the line lay and tension are not 100% correct a mini loop will appear. 
Of course it's not always possible to wind in evenly especially when your rig hits weedbeds etc, this is why many experienced anglers choose to pump the rod sea fishing style. By pumping the rod tip up and dropping it quickly slack develops, then wind in using fingers on the line to maintain a degree of tension. Pumping the rod on weedy or snaggy waters with appropriate tension will give you a far better line lay than straightforward continuous winding. If you already were aware of these facts then I am teaching egg sucking and apologize, if not it's a little food for thought. 
Dave Chilton 
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