How to grow as much algae as possible?

[redrager]

To start, I’m trying to make a “kelp forest” urchin tank that can support as high a density of them as possible. Starting tank for this experiment is a 39 gallon that’s 20 inches or so deep
Current plan is to just introduce a bunch of caulerpa, and some live rock heavily infested with hair and bubble algae and whatever else. What would be the best light to use to get all of that to grow as wildly out of control as possible? I just want lighting that will at least be normal and white looking and not super ugly, nothing blurple. Could I straight up use a grow light like people use for weed? Assuming I’d need a uh sterilizer to keep the water from going green also?

Thanks for any help, most of the info out there is geared to doing the total opposite of this lol

 

[shwareefer]

High nutrients, lots of light. Preferably some natural sunlight hitting the tank from a window. Normal reef lighting or grow light will work - algae's not that fussy. Bear in mind the nutrients need to be restrained enough to not hurt your urchins.

 

[jda]

You want medium N and P, not high. Too high and you will growth limit most macro algae. You also need to keep the N and P low or else the urchins can slow down and die too. I would shoot for 3- 5N and P of about .05 to .1, or so. That is more than enough for macro, but low enough for most else. The urchins might like some coralline too, so the lower the N and P the better for that too.

Some of that algae can go sexual and wreck your tank, so study up on it and select well.

GE 6500k T5s work great for this... not too yellow and definately not too burple.

 

[YOYOYOReefer]

any old used metal halide bulb will grow algae, its part of why people change the bulb every 9 months or so.

 

[dedragon]

For lighting i would stick to these, cheap, led, waterproof, and will last a long time before needing replacement
Amazon product ASIN B07PJH6YZ1

 

[dedragon]

you dont really want bubble algae as urchins wont really eat that to my knowledge

 

[Brady4000]

you dont really want bubble algae as urchins wont really eat that to my knowledge

Mine won’t. Wish it did.

 

[N.Sreefer]

Any 6500k light will work well I use sun blasters myself because they're high quality ho t5s with good reflectors/very good color blending and go on sale multiple times a year. If your looking to grow tons of algae just dump some reef roids in eventually the tank will be nothing but a mass of algae haha. In all seriousness you could use seachem flourish/excel (sparingly) to fertilize the algae. Miracle grow works but it separates out clumps and makes a mess, it also has higher copper than I would add with inverts (although my shrimp are fine with it in freshwater).