People can use whatever bulbs they want. I've been using HID's for years and have used numerous brands of bulbs.
Those expensive bulbs diminish in light quality just like the cheaper ones over time. They are not 6 time better than the less expensive Vivosun bulbs but they cost 6 times as much for 600 watters and 4 times as much for 1000 watters.
Everyone keeps saying that HID is old technology and it is which is why it's not difficult for many of these newer companies to sell comparable bulbs for much cheaper. It's already well known technology and easy to produce.
The OP asked about replacing a 400 watt bulb. They can spend $70 for a Hortilux or $14 for a Vivosun and end up with the same results. The spectrum of both lights are almost identical. Both are enhanced spectrum super HPS bulbs.
I stand by everything I said. It has nothing to do with being stubborn.
Hortilux
Vivosun
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