I've got the big power producing crystals, but they only work when I'm power-poor (never happens because of collector spam)

The factoriopedia says "burn it in a flare stack" but the flare stack can only connect to pipes and not fibre optic cables.

The unstable gem (the item needed for beryl) recipe chain results in an excess of pure light so it doesn't work.

Is there a way around this? I can't figure out how to make these crystal seeds with all this pure light clogging up my system

I could add a "venting" recipe in the next update :D

I could add a "venting" recipe in the next update :D

I got around it by having rows of manipulators that constantly recycle the two calcite/quartz recipes between each other surrounded by beacons. It takes up a load of space and it's slow but it works, yes I think it'd be appropriate to have the option to vent.

It's controlled by power switches, activated when the pure light in the manufacturer goes over 48.

Or even just an option for the power crystals to run constantly even when the grid is satisfied

Also, I've covered 5 times my factory size with collectors connected via fibre optics, but I still only produce a trickle of unstable shards. I think the collectors need balancing with way more light produced, or, unstable gems need 1 shard rather than 5

IDK, I don't know how you wanna balance the game, but covering the map in collectors and cables just to get 10 beryl a minute is frustrating

Ill add a venting recipe, about beryl im balancing the recipe and probably adding a prod technology in the next update

For people still looking for how to do this, you can do some fluid voiding fairly simply.

Instructions to make a fluid void: Build a (voiding) refraction plant (that wont be used for crafting), a constant combinator with a signal of 1 unstable gem, and a decider combinator. Hook the constant and decider combinator output to the voiding refraction plant with a red wire and have the voiding refraction plant set its recipe by signal. Now have it also read contents, and run a wire to the input of the decider combinator. With a different color wire, connect the input of the decider combinator to your refraction plant(s) making the pure light and set them to read contents too. Finally, configure the decider to output -1 Unstable Gem signal (to counter the constant combinators recipe and unset the voiding plant) IF the pure light in the void plant = 40 AND pure light in your Flourite discharge plant > 40. The last number there is mildly arbitrary and will need to go up if you have more than one plant making light. Make sure you have fiber optic cable to connect your void plant to all your other pure light.
The end result of this is that whenever you have an excess of light, it'll totally fill the system and back up into the source plant, causing it to go over the threshold. That'll unset the void plant's recipe, deleting all the light it had inside it. Then a tick later, the decider combinator will stop outputting -1, setting the recipe once more, and letting the void plant fill back up. This should delete 40 pure light from the system every 2(?) ticks, which should be more than sufficient. Note that this only deletes any excess pure light over what the system can hold, so it should stay filled to 100% otherwise, so you can keep using refraction generators without problems.

Blueprint for the lazy, I can't figure out how to make the factorio forums word wrap this, but you can triple left click to select it all:
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