Plants size is it ok ?

They look healthy enough, but 100w LED isn't going to set the world on fire. Seaweed isn't a grow nutrient on its own, more of a tonic for both the soil and your plant. If wanting to keep it organic as possible, try some bio vega made by bio canna or flora nova grow one part made by GHE. Both these products work outstandingly well and have their partner bloom nutrients, namely bio flores and flora nova bloom one part. All these are simple to use, requiring no mixing or any other products to buy. Both are also very concentrated and only need small amounts, meaning one bottle of each will last many, many plants or multiple grows. Half strength is also plenty strong enough. Another product to consider is organic grow and organic bloom by BAC. I have used the former two nutrients for many years with excellent results and am only trialling the BAC now, but results have so far been excellent too. Hope this helps,.... Organoman.