hi my L104 clown plecs will not eat veg ie cucumber etc. they will only eat bloodworm, shrimp pellets etc. they obviously have bogwood as they are a major wood eater. could this be a problem if they are not having any vegitation in their diet , also they will not eat algae wafers.

Too much protein has been known to cause intestinal problems in vegetarian fishes. If the fish is eating lots of wood and only a bit of bloodworms & shrimp pellets, then it should be ok. However, if the bloodworms are the main part of its diet then future problems might arise.
See what happens if you don't feed any bloodworms or shrimp and only offer cucumber or pumpkin for a few days. Put the food in at night after lights out as the catfish are nocturnal. Also try using cooked and raw veges and see if that helps. You can also grow algae on the glass and the fish should graze on that.