Algal Bloom Dead Zones

TSP, tri-sodium-phosphate (Na3PO4) was a common cleaner up until about the 1970’s when the massive environmental problems associated with phosphates were addressed by the removal of these chemicals from most products.  TSP is still available in home improvement and hardware stores, as well as on-line, but just because you can buy something doesn’t mean you should use it, at least not without understanding what it is and what the problems associated with it are.

The Trouble with TSP

One thing you may not realize about TSP, which is widely rumored to be very safe and even benign, is that it is in fact highly alkaline, with a 1% solution having a pH of 12 (lye comes in at 11) the highest number on the pH scale, with higher numbers being more alkali.  This means it can and will burn unprotected skin and eyes.  You must read those caution labels carefully.

If you intend to use this product anywhere around plants be sure that you first soak them well with fresh water and then as soon as possible rinse them thoroughly.  That may help protect them.  Products like MoldStat Plus don’t have these same problems and precautions when used around plants.  In fact, they are often used in greenhouses for mold prevention!

The problem is the phosphate

The reason phosphates were banned in the first place is because they cause algal blooms that suck all the oxygen out of bodies of water, killing all life in them.  Creating Dead Zones Because of this, you must be certain that any runoff cannot possibly enter any streams, rivers, ponds, lakes or other bodies of water.  If you have a pond or body of water on your property, you can’t be too careful with TSP.  If it gets into your water feature, you may well have just ruined it for fish, and it won’t be pretty when full of foul, slimy green algae!  MoldStat Plus, and products like it, won’t harm bodies of water.

You can’t just let it run down the sewer drain without care.  In fact, depending on where you live, it may be against local, county, or even state environmental regulations and law for you to even use TSP in the first place.  Using TSP without appropriate precautions could put you in the position of, even unknowingly, breaking the law and facing big fines and penalties if you are caught.  Products like MoldStat are safe and legal to use anywhere in the United States.

TSP Mold removal

If you want to remove mold or mildew you should know that while TSP can remove mildew pretty well, especially if combined with bleach which will remove the color while TSP alone won’t, you should be aware that TSP won’t prevent the regrowth of mold, like products in the MoldStat line can.

Using TSP and bleach to clean your roof is the recommended procedure according to shingle manufacturers, and it is a great idea if you plan is to buy new shingles!  TSP is a strong enough alkali to literally dissolve grease, tar, and other petroleum products.  Your asphalt shingles are just such a product!  TSP could not only be harmful to the shingles themselves, but any metal, especially aluminum flashing, drains, and gutters can be permanently stained by TSP.  Ad to it that TSP causes Algal Blooms, and you will ask yourself why you are using a product that grows algae, to try and kill algae.

Adding bleach just compounds the problem as bleach has a profound drying effect on shingles, potentially causing them to crack, and bleach can etch and dissolve aluminum metal fittings. The MoldStat line of products brings none of these problems with them.  Obviously it would be disaster to try to clean aluminum siding or roofing with TSP or bleach for exactly the above reasons!

Bad Idea Bathroom Cleaner

One of the rooms most commonly affected with mold in households is the bathroom and TSP is a disaster waiting to happen in the bathroom.  Many bathroom fittings, especially shower surrounds, are made of aluminum which is off limits to TSP.  Even chrome fittings can be pitted and permanently stained by TSP.  And you absolutely do not want to get TSP on grout!  TSP is used to dissolve and remove grout spills and excess during the construction of bathrooms!  TSP will soften your grout and make it susceptible to failure.

In addition, TSP is not necessarily safe for all glazed ceramic tiles and the only way to find out if it is safe for your tile is to test it.  It is too bad for you if your tile turns out to be non-resistant to TSP.  Again, the MoldStat line of products is safe for aluminum and chrome fittings and will never harm grout.

When is TSP ok?

The reason TSP is sold in hardware and home improvement stores is because it is invaluable as a painting preparation agent.  This is why it is most always stocked in the paint section.  TSP is used to de-gloss paint, it removes the shine from the finish, and this is exactly the type of paint most always used in bathrooms and kitchens, the two rooms most commonly negative affected by mold.  Even non-gloss, or flat, paint isn’t immune to the effects of TSP as it is designed and used to open the paint pores, effectively roughing the surface equivalent to using sandpaper, to make new paint adhere better.  If you are planning on removing the mold from your painted surfaces and then repainting, TSP is a great choice!


Know your chemicals = Clean Safer

Always be sure you know what a product is designed and intended to do before you use it!  If you just want to remove the mold and not the paint, perhaps a solution from the MoldStat line of products would be a better and safer choice.

MoldStat: a safer alternative, environmentally friendly, non-damaging to metal, paint, wood, ceramic, and grout, and easy to use: an all-around better solution to your mold situation!*


*when diluted to label recommended usage strength for a specific job

One thought on “Trouble with TSP – tri-sodium-phosphate”

  1. Jackson w says:

    Then why do roof shingles recommend using tsp and bleach to clean dy algae covered asphalt shingles? This make no sense.