H2O2 Dosing?

[asylumdown]

At this point I can say with pretty high confidence that hydrogen peroxide is both one of the most useful and safest tools in a reefers toolkit.

It's not completely without risk, but you have to dose a massive amount to harm anything. I use both 3% and 29% depending on what I need it for. Stupidly, I've been storing my 29% in a 3% bottle from shoppers with a home made sharpie label on it. I messed up once and grabbed the wrong bottle and used 45mL of it my tank. A few of my acros browned out for a few days, but that was about it.

If you're spot treating cyano or Dino's with the pumps off, 3% works great. If you need to really clean off a section of more persistent algae, or are looking to broadcast dose to systemically inhibit cyano, 29% (or 30 if you can get it) is probably easier to use. You can also dilute 29% however you want. I'll sometimes make 7% solutions cuz they have a bit more kick when it comes to killing algae, and you can use more of it.

ETA: when I used the 45 mL of 29% by accident it was with the pumps off and about 50 gallons of water drained from the display. I don't think that amount would have caused a reaction of it was full and the return pump had been on

[Aquattro]

I know my LFS guy used it to spot kill algae, but I hadn't thought of regular use to just sparkle things up a bit. Sounds like it would work for that. Maybe?

[asylumdown]

I've never noticed the tank being any sparklier after using it. Peroxide Loooooooves organics, but theres ALOT of organic material in a tank, probably so much that to noticeably decrease it in the water column for more than a few minutes you'd need to be dosing enough peroxide to kill all your fish and corals. There's also a lot of complex organisms with cells filled with peroxidase whose sole purpose in life is to instantaneously break it down in to water and oxygen on contact.

What it does do at relatively low concentrations is inhibit the photosystems in cyanobacteria - Something about the structures they use to photosynthesize being particularly sensitive to reactive oxygen coupled with poor metabolic pathways to eliminate it, likely related to the fact that cyanobacteria evolved when the atmosphere had very little oxygen in it or something. There's lots of cyanobacteria in tanks all the time, just not necessarily in the nasty biofilm form that people post about when it gets out of control. If there is low levels of cyanobacteria in the tank staining the water or causing rocks and sand to have a darker colour or stick together, dosing peroxide might cause a noticeable change in the visual 'cleanliness' of the tank - but that's a wild guess based on a totally unsupported assumption.