08/28/2026
I saw a recent post, comparing D2 to wet and forget . Which I unfortunately cannot find at this time and believe it may have been taken down.
I would like to dispel some rumors about them being equal. They are not.
Whoever wrote that email is playing fast and loose with chemistry and marketing speak. Here is a breakdown of why that claim falls apart:
1. The pH Comparison is Backward
Wet & Forget actually has a pH of around 8 (making it slightly alkaline).
D/2 Biological Solution has a pH typically cited around 9.5 (also alkaline).
If the email claims that Wet & Forget has a lower pH than D/2 and that makes it safer, they are either misrepresenting their own product's pH or misunderstanding how pH scales work. Both products are slightly alkaline, meaning neither is a harsh acid, but Wet & Forget's pH is certainly not lower in a way that gives it a preservation advantage over D/2.
2. The Real Issue: Salts and Surfactants
When it comes to historic or delicate stone (like marble, limestone, or sandstone), pH is only part of the story. The real danger to old masonry comes from salts and harsh surfactants.
The Salt Problem: Many cheap or general-purpose outdoor cleaners (and even some DIY mixtures) contain soluble salts. When those salts get into the pores of a stone and dry, they recrystallize. This process (known as salt weathering or subflorescence) exerts immense internal pressure, causing the stone to spall, flake, and crumble from the inside out.
D/2's Pedigree: D/2 was specifically formulated by conservators and is trusted for use on national monuments (like Arlington National Cemetery and the White House) precisely because it is free of harsh acids, harmful salts, and bleach.
3. Purpose-Built vs. General Purpose
Wet & Forget is a fine, budget-friendly, general-purpose outdoor cleaner meant for roofs, siding, decks, and concrete driveways. It relies on a blend of alkyl ammonium chlorides to slowly kill moss and algae over time with the help of rain.
D/2 is a specialized architectural conservation cleaner designed explicitly to lift biological staining, stubborn carbon pollution, and lichens from fragile historic masonry without altering the stone's chemical structure or leaving behind damaging residues.
The Verdict
Treat that post a d claim as standard corporate sales spin. Wet & Forget is trying to position a generic big-box cleaner as an equivalent or superior alternative to an industry-standard conservation product. For delicate stones and headstones, sticking with a trusted, conservator-approved cleaner like D/2 is still the gold standard. Will always be my choice and number one go to.
