Jack's Magic Blue Stuff is one of several products that prevent metals in the water from causing stains on the pool. If you have a significant level of metals in the water then you need it. If you don't have metals in the water then it is wasted money. Metals tend to be fairly common in well water and quite rare in city/public water. Most pool stores can test for metals in the water or you can get a special test kit that can test for metals. Most likely if you have never had metal stains you don't have metals in the water.
Also, some new pool builds require it as a part of the warranty requirements. This is because it can help prevent scaling on new plaster. If the pool store is testing your water and it is positive for copper or iron then you need it. (unless you are adding the copper yourself on purpose, either with an ionizer, mineral cartridge, or metal algaecide--none of which we really recommend in this forum.) Be aware that as a general group metal seqesterants are designed to be most effective on certain metals. For example, the Blue Stuff is most specific for copper (has the highest chelation index for copper). Others products might be more specific for either iron, calcium, or manganese or might be a general purpose one. These usually are equally effective on iron and copper but less so on calcium. There are othter ones, sometimes called calcium hardness reducers, that are more effective on calcium but will also chelate other metals.
Thanks for input. The bottle was left here when they started the pool up. No one said a word about it, it was just left in a corner with the muric acid and DE. So I took it upon myself to read directions and add to pool. I have sorta been hit or miss with it though. However I am now out of it and was not sure if it was really needed. Typically when I have pool store test my water they do not test for metals however I did get it tested on Friday and next to copper and iron it stated 0ppm. Usually it says not tested.
Hmmm I am not sure what metal stains look like. I have lime stains on the tile, where the water fall is. What do metal stains look like?
Iron is usually brown to tan and an easy check is to hold an ordinary vitamin c tablet on the stain. If it is iron it will disappear in a about thirty seconds. The stains are easily treated with ascorbic acid. Iron can make the water yellow to rust colored. If the pool has a blue surface, as many do, the water will have a green cast (yellow + blue = green). Iron staining is most common in fiberglass pools but can occur in any type of pool. Iron stains ofen occur from using salt that contains anit caking ingredients (yellow prussiate of soda--an iron salt). This is why I like the larger crystal solar salt for pool use. It will not contain this ingredient! some of the finer salts might contain it and not list it on the label!
Copper can produce grey, black or brown stains. The grey and black ones are very difficult to remove. It can color the water green. (clear green, not the cloudy green associated with algae. Copper usually is introduced into the water from algaecides, ionizers and 'mineral' sanitizers, and copper heat exchangers in pool heaters if the pH drops too low. Sometimes it does come from the water supply, expecially if copper plumbing is used.
Manganese produces grey stains. They are fairly easy to remove with oxalic acid or possibly ascorbic acid (test with the vitamin c tablet first to see if the ascorbic acid will work.) It can color the water pink to lanender to purple.
Cobalt spotting only occurs in fiberglass pools. It starts as tiny black spots in the gelcoat that continue to grow. It is usually treated with oxalic acid or ascorbic acid. Most of the newer gelcoats are more immune to cobalt spotting and there is some evidence that maintaining a calcium hardness above 150 ppm helps prevent it from occuring.
Coloration of water from metals will usually happen right after shocking so if your water turns a color after shocking suspect metals.
Lime (usually called scale) is also a metal stain. The metal in question is calcium (yes, calcium is a metal!). It produces tan to white stains on pool surfaces. High pH is the most important factor that leads to scale deposits. Scale is difficult to remove and in worse case you must acid wash. Lowering the pH for several weeks with constant brushing sometimes helps as does a no drain acid wash procedure. Some commercial calcium hardness reducers and scale removers are sometimes effective. Spot scaling on tile can often be removed with a pumice stone or by acid washing or a combination of both. One thing I have found effective is a mixture of tile soap and muriatic acid for removing scale from tile. Use 1 part muriatic acid to 5 parts of tile soap.
WOW - great info. Thanks so muc!!! Some of my stains are a tan/brownish color so I will check the Vit. C thing this week - if and when rain clears out . Lime has been a devil for us and we have had to chisel some off already as it had gotten so thick (our pool school was nothing and no one told us about ph, etc...). To do a muric acid wash, what do you put the acid in? Our's is under the waterfall so I can not figure out a way to get under the waterfall to scrub it unless I am in the water. I truely appreciate all your help!