I have use the larger starter plugs and love them, however; decided to order the 1.5" as I wanted to use them in combination to the smaller baskets to put them in for growing my plants in water. Also, had the idea to start my tomato, pepper, eggplant and thyme seeds in the smaller plugs. When the seeds get a little height to them, I plan to transfer the plugs and place them in 3" sq. peat pots with potting soil around the plugs so the plants can continue growing. After the roots grow out of the peat pots, then the plants will go into my garden. So far my seeds have sprouted and have grown almost an inch tall. The plugs that I have planted varieties of leaf lettuce in will be put into small mouth canning jars with the fertile water for hydrophonics as soon as roots are visible on bottom of plugs. So far I am very pleased with the product. Will know more as the season progresses.I read some of the reviews for this item prior to purchase claiming they were not name brand. But they sure look legit to me. If they aren't Grodan, they are same quality and perform identically. These are great quality and I believe they absolutely are the name brand item, they are just bulk packaged so the sheets are not wrapped individually is the only difference. I will be ordering again.Liked the size allowed for increased rootsI've tried other planting mediums but rockwool is hands down the best so far. Used for lettuce and celery seedsGreat quality but holes were misaligned. No biggie but definitely a quality issue. Also grows algae quick.Works well! Keeps moisture well! Arrived on time too.Always works easily in hydroponics. Plants seed every time. Not good if planning on transplanting more than 3 weeks. Plugs will dry it when plant starts growing.We use these in our aquaponics system and have had to research how to prepare them for use. Germination is usually pretty quick. Just right for what we need.