Hello! I just ordered 2 bottles of FerriTabs. I’ve been battling iron stains in my pool for 3 years so I’m really hoping they will help. I plan to do an ascorbic acid treatment before adding the FerriTabs. I have a 20,000 gallon pool and I’m a little confused about how many FerriTabs I should use. I read that one FerriTab treats about 3,000 gallons so I assume that means that I would need about 7 in my skimmer basket after the ascorbic acid treatment. However, I also read on your website where you said you usually add 1-3 at a time. Can you please clarify? I don’t want to use too little or too many. Attached is a photo of my pool. You can see the iron staining and also the blue-green water due to the iron.
Thanks!
Yes, wait the time frame and then backwash – as long as the ferritabs are attaching to the iron the backwash water will be green/orange/rustybrown color – the color depends a bit on what your other water chemistry numbers are.
If the alkalinity is lower (around 100) and the ph is at 7.2-7.4 then the water should be good at pulling metals off the surface of things and the ferritabs can do their job. Ascorbic acid does use up all available chlorine in the pool – so you will have to add more. But if you add too quickly before the ferritabs have a chance to attach to the iron molecules then the iron will be “pushed” back onto surfaces of things with the addition of a liquid chlorine which as a really high pH (like 12). Tablets have a low pH of 2 or 3 so they would be okay to continue using during ferritab treatment. If you have salt water/chlorine generator it’s a good idea to add 1/2 gallon of muraitic acid, the ferritabs, and then continue to let the generator make chlorine.
If you backwash after this initial treatment and you get orange/ then retreat with 2-3 more ferritabs and backwash after another 24-48 hours – then you should be able to resume the normal maintenance. If you have to add more water from the hose add one ferri tab each time you do so it can catch some iron right away.
Hello! I did my ascorbic acid treatment yesterday and then added 3 FerriTabs in the evening. My sand filter pressure only went up 1 psi. Is it supposed to go up more than that? Do I still backwash after 24-48 hrs or wait until the pressure goes up more? Should I add more FerriTabs? Sorry for all the questions – I just want to make sure I get the iron out before it restains! 🙂
Yes after you do the ascorbic acid then add 3 tablets, circulate 24-48 hours, backwash or clean the filter and repeat until your backwash water is running clear and you don’t see the discoloration. Then just add one every time you top the water off in the pool for prevention…they are wonderful!