F9 efflo stained concrete?

First time i have used f9, attempting to red dirt/clay stains out, i went over & over & over directions, i first tested a spot using 3:1 (water:f9) very little results, so i went up to 1:1 ratio & ended up with this… what did i do wrong???

Itsvhard to say. It looks like that part wasn’t cleaned. I’d suggest contacting f9 directly. Theyre pretty good about help in g thier customers


Thanks, i contacted them yesterday evening & they replied fairly quickly & im still waiting to hear back from them today, & i have done a few tests on my driveway at home using the same method as well as lighter & stronger solutions as i did with the concrete in pic & have had good outcomes, nothing at all like the pic…

maybe they had some type of sealer on it? Just a guess

No sir, not to their knowledge.

Did you use efflo or barc?

Efflo, guess i shoulda stated that in the beginning.

You probably just etched the concrete. Efflo is hydrochloric acid. Barc is phosphoric acid. Either could etch it left for to long or not diluted enough

Ok, i guess next question is anyway to get the “original color” back or lighten up the etched area?

The etched area is likely the area that is lighter in color. Etching opens the pores in concrete by the acid basically dissolving the surface. If certain areas had a sealer, oil, or grease those areas may have been prevented from even being etched. That could be why you’re thinking the etched areas need lightened up when they actually haven’t even been etched like the lighter areas. It almost looks like you allowed the cleaner to sit longer on the lighter areas and etched them more than the darker area because you can see the cleaning lines. Did you clean it in sections or was it all at once?

I cleaned “area 3” at 1 time with the f9 efflo. Areas 1 & 2 had no f9 applied & is what the rest of the patio look like…

Did you ever find a way to fix this? Or did you find out what the issue was?

No sir! The home owners went with staining the concrete, i was actually talkin to somebody about it yesterday & it still bothers me not knowing

Looks like you’re not the only one.

I am curious why F9 Efflo was used? I have not used that product. Is it normal for the F9 Efflo to darken the surface it is applied to? If so, was the the original intention or was the intention to lighten or brighten it and used the incorrect chem? I feel a bit lost trying to understand what is going on in this example.