Any real benefit? Seems like a decent idea, similar to compost tea idea, but rather expensive. A safer alternative than concentrated fertilizers?

A little goes a long way in terms of effectiveness so the cost is somewhat reduced in that way.

If you have direct access to seaweed and it is rinsed well first to remove salt then it can be a great mulch too according to coastal residents.

Dave

Alaskan Fish Emulsion (ok) and Neptune's Harvest (best) are very different from each other in what they provide to the plants and how quickly due to the processes used to make them.

Same applies to the various kelp/seaweed products as they depend on harvest location for nutrient levels and preparation methods used for how much of what is usable by the plant.

But in general the straight seaweed blends have greater concentrations of micros and macros, auxims, and amino acids than the straight fish products do. But they contain essentially no nitrogen or phosphorus like the straight fish products do.

So blends of the two - fish and kelp/seaweed - cover all the bases.

Dave

Dave