Hi ksvet, Two possible suggestions. You could tie a filter at the target end of your siphon - something like one of those bags you might add hops to in beer making. My concern would be that a simple filter would quickly fill with the seeds and prevent your wine from flowing into the target carboy but if you filtered through a hop bag or some other kind of bag and if the bag was large enough to accommodate all the seeds then the bag would not in fact block the flow.
The other suggestion is to create a whirlpool in your source carboy by stirring with a long spoon or paddle. The whirlpool will result in the seeds tending to collect towards the middle of the carboy - like tea-leaves in a stirred cup of tea - and you then siphon from the edge. Now if you have a large stir plate and a magnetic stirrer I think (but am not certain) that you might be able to keep this whirlpool effect going until you complete the racking thus avoiding the vast majority of the seeds. Without such a stir plate I suspect the seeds will slowly move back from the center so a filter may be a useful adjunct.
