Using HydroPureTech cartridges to deal with Iron

[PoolDoc]

Do you have a skimmer?

If you do, there's a way to use cal hypo tablets in conjunction with a sand filter to continuously remove iron and other metals.

[BJohnston]

Yes I do. I have been doing more reading and see suggestions to use both Cal Hypo or Tri-Chlor.

I am leaning towards using the Tri-Chlor because my CYA is low and needs replenished. I also have CYA I can add on its own so I'm not sure which way will be the best.

I need to retest my numbers when I get home, I did not get a chance to this morning before heading off to work. what are the upside/down side to using Cal-Hypo vs. Tri-Chlor assuming I need to add CYA anyway?

[PoolDoc]

For dealing with iron, cal hypo is much better. The only downside to cal hypo is that you MUST use it the way I instruct you to do, or your will end up with calcium that is too high. Well, I guess the fact that you may not need as much as you'll have to buy is a downside. It will keep till next year, but will be 'stinky' when you open it next spring

This is the ONLY product I've found that you'd want to use:
CCH Calcium Hypochlorite Tablets 50 lb bucket

The Arch cal hypo tablets contain 25% or more magnesium sulfate, and you don't want that in your pool.

[BJohnston]

Wow, that will be quite an investment. I don't know if my iron issues are that severe to justify the cost currently. Do they have that in any smaller amounts?

My fiberglass steps seem to be the only thing being effected currently. They are orange/brown. I have 1.75 lbs of natural chem stain free, I know its only Citric acid, and could get a better price elsewhere, but I was in a rush and decided to buy it at the local Pool "Steal" while I was there getting some misc fittings and parts. I am going to by a culator 4ppm but haven't clicked the purchase button just yet.

I have a party tomorrow and was going to try to minimize the ugly brown steps and make it look half decent so that people aren't afraid to swim or have everyone ask me the same ???'s about it. I was hoping to just get it managed and then address it permanently afterwards. I know there are a lot of different options that people have used so like I said in the beginning, I'm just trying to do my homework before I go to far in the wrong direction.

I successfully used HTH metal control to reduce/remove the staining (aka put it back into solution) but now its back again. I assume due to high chlorine from shocking recently. So I'm assuming that I can replicate that with the stain free. Am I wandering down the wrong path with this one or can this be an ok start/temp fix?

[PoolDoc]

Do NOT use citric acid.

If you want to re-dissolve the iron, use ascorbic acid. But remember that NEITHER are compatible with chlorine.

You need to get clear on the difference between dissolving iron, and removing iron. The ascorbic acid will help redissolve iron where it has stained surfaces. But it will do NOTHING to actually remove it from the pool -- rather it just *moves* the iron from the stains ON the pool to the water IN the pool.

By contrast, the cal hypo will do NOTHING to help with the stains, but it will enable you to remove the iron that is IN the water.

The expensive of the cal hypo is not an 'extra' expense, like ascorbic acid will be. Rather, it will become THE way you chlorinate. The reason for using it is that WHILE it chlorinates, if you use it correctly, it will ALSO remove iron FROM the pool water and deposit ONTO the calcium dust collected by your filter. From there, both the dust and the iron will be actually removed from your pool each time you backwash.

[BJohnston]

PoolDoc,

I thought that citric & ascorbic acids basically worked and behaved the same way, abeit ascorbic acid was more efficient? Just curious on why you recommend not using citric?

I guess I should clarify why I said "citric" acid. I wanted to use Natural Chemistry's "Stain Free" which they advertise as *100% citric acid* maybe this is simply a mis-labeling? They also have an Extra Strength that they say is 100% ascorbic acid.

Sorry to give the wrong impression earlier... I understand the differences between "removing" and "dissolving" the iron back into solution. I also understand that once the citric or ascorbic acid is applied, the iron is still in my water and can "fall" out of solution again and re-stain things. I do not want this to happen. I also understand the incompatible relationship that chlorine and these acids have with one another.

I am interested in hearing more on your method for using cal hypo to remove iron and for how it will effect my calcium numbers. I will have to re test to see, but the last time I checked, my Calcium was up around 290.

[PoolDoc]

Citric acid combines with chlorine to form toxic trihalomethanes. It's not clear whether this is an issue on outdoor pools, but since ascorbic acid works better, is cheaper (when purchases as ascorbic acid rather than pool chemical) and doesn't have this issue with toxic byproducts . . . citric acid ends up on the DO-NOT-USE list.

Plus, it irritates me no end that Natural Chemistry doesn't provide users with enough info to use the products effectively.