I have searched this site, and googled some information, but am still confused. I personally have large river rock (instead of mulch) on the northeast side of my home. It is getting darker, with algae on it. I did spray it with a pump up sprayer in a test section, but it didn’t seem to remove much. The algae turned the white color on the surface so I think that it is dead, but not sure. I mixed 1 cup per gallon of SH (8.25) with a little soap (about 2 ounces).
I couldn’t get 12% SH, I’ve checked every store in my area reading the bottles. Bottles that were unlabeled for percentages I actually called the companies and only received two call backs. My buddy installs pools so I went to his store and the best that they had was 10%, and his supplier is charging him about 14 a gallon (that would be my cost too). He had shock it, maybe I should try that?
The temperature was about 54 degrees and warmed to about 61 for a high that day. I only did a small test section. I sprayed it and just let it sit, what appeared to dry quickly was re sprayed (figured it sucked into the rock).
I know that stone is porous, so is it that I need to make a “thicker” mix, or is it that SH won’t seep into it enough. River rock costs about $45 dollars a ton if you haul it yourself, not including all the time you spend cleaning it before spreading it. Most rock/stone places deliver dirty stone and you don’t want that in dirt in your “bed” if you did it right and put down fabric.
I’m sure that some of you wouldn’t waste your time with this, so I apologize if it seems trivial. I am experimenting with various things I am learning here so I can figure out what I will do next year. I figure a cheap clean up of river rock would save people lots of time and $$ so it might be a decent thing to add with deck washing and possible re staining.
this brought up some very odd results in google, while on here it was more about exposed aggregate drives and walkways. One guy on a video suggested putting the stone in sunlight to kill algae, others said vinegar, while other said pressure wash, etc all over the place. The guy saying put algae in sunlight made me laugh, unless he is using it for bio-fuels.
I figured people might want to see pictures to know what I am talking aobut. The one picture is river rock that is old, the other picture is rock that is newer (about 1.5 years old)
If using 1 cup of 8% sh per gallon of water your mix is way too weak. I’m talking like .01% or something. About the weakest mix we use is for house washing and that’s about .75% to 1% because vinyl doesn’t take much. When you get into more porous substrates like brick, stucco, or stone you have to increase the strength. I’d aim more for like 3%-4% which is almost a 50:50 mix. Half a gallon of your 8% and half a gallon of water. Be careful if you have any plants nearby. Just be sure to dilute the heck out of it afterwards. Let it dwell for 10-15 minutes misting to keep wet and rinse. It might take a few applications but I doubt it. They don’t look too awfully dirty.
When you say he had “shock it” what are you talking about? If it’s powdered don’t use it. Only use liquid pool shock that is SH and nothing else from there. 8% is fine to use if that’s all you have access to but you’ll have to see if it’s strong enough to use when down streaming. It just depends on your injector and pressure washer. If you pulled it straight it should be. I’d still try and find a source for 10% or 12.5%. It sounds like the decision is going to come down to cost. There are a few other members here from the PNW. I think I recall them also saying sh is expensive. Maybe @Sasquatch can help. He might remember who else is from up your way and bring them into the conversation so they can recommend where to get sh.
Spray it with 50-50 mix and leave it. May need to do a couple of times. Rain will wash it off or you could just rinse off with hose after a day or so. That lichen will take awhile to come off.
Thanks, it is lichen. I wouldn’t have thought of a 50/50 mix. We hadn’t had this before, but the last two springs were colder and wetter than normal. I guess this is the perfect breeding ground for algea and fungus to get together and propagate.
Thank you. There are no plants in the bed I am treating.
Yeah the shock it was powder. Is it because the powder won’t mix as well as a liquid? I am not in the PNW, I am in the north east. I got my buddy to call his chemical supplier (which is a pool manufacturer) and they don’t have SH in 5-15 gallon jugs. So, I think that they might be a middleman for the SH. He is my friend, so I am not pushing him to do business (chems) with anyone other than his supplier, as they have a rather cozy relationship. I told him I would look at another pool place for SH and he was OK with it. Can’t be friends with someone and then they see you shopping at the competitors store. Not cool.
My bad. For some reason I thought you were at the other end of the country. Where at in the Northeast? There are guys on here from up there too that can probably direct you to some SH. You can usually get pool shock at Walmart or Lowes but it’s out of season for them. The reason you can’t use powdered pool shock is that it’s not Sodium Hypochlorite.
Ok, I didn’t actually read the ingredients, just saw it next to the rest of the pool chems. I did try walmart and lowes for SH, they didn’t have anything (both had regular 6%). Home depot was the only one that had 8.25. I figured I could order it online, but since I am experimenting I didn’t want to order a lot of stuff.
Thanks for taking the time to reply, I appreciate it. I just came in from my latest experiment with the river rock and a stronger mix on a small roof overhang. I will go back and reread the mixing ratios.
