Quote Originally Posted by mbar
Waterbear, Pamsel had put in a lot of sequesterant, that is why I am having trouble thinking it is copper - although the first set of pictures she has here (the last two) the water looks clear green, which does look more like copper coloring the water. But she is losing chlorine fast
Yes, during the day and she has very little CYA in the water...she said either 0 or 25 ppm! Her chlorine has been holding at night and burning off during the day!
, and the stuff in the last picture she posted looks more like algae than anything.
I suspect it is dead algae and for some reason her filter is not getting it out
My thought is that if she lowers the ph and alkalinity, the chlorine will be more effective in killing the algae, plus you know high chlorine levels and high chlorine are what make metals fall out of suspension - there doesn't seem to be any staining on the steps in the first set of pictures.
But she has put in a LOT of sequesterant!
This is a very confusing case - maybe you can help - you are great with the chemistry - what is the difference between a chelating product and a sequestering product?
From my understanding very little, It has to do with how it deactivates the metals. chelating agents have a heterocylic ring struture that forms a complete ring with the metals, sequestering agents form stable non reactive compounds with the metals but are not necessisarily in a ring structure. Chelating agents will sequester metals but not all sequesterants chelate. EDTA (reagent #3 in the CH test is a chelating agent. It chelates the calcium in the water and when there is non left to react with the indicator it changes color from pink to blue. The indicator itself is a chelating agent that forms a pink complex when metal are reacted with it and blue when there are non. EDTA is a stronger sequsterant than the calcon indicator so it will 'unhook' the calcium and other metals from the calcon and 'hook' it to itself Phosphonic acid derivatives are what is usuallly found in metal seqeusterants. This group of chemicals tends to create very stable compounds that are more resistant to temperature and ph effects than EDTA, Sequestering is a much broader description. Chelation is a specific type of sequestering. The terms tend to be used (incorrectly) interchangably. By the way, sequstering products are rated by their 'chelation value or ratio' ( how stable a compound they form)!
I also think there may be a filtering problem - because there isn't much coming out with the backwash - and the pressure is at 40, when it ususally is aroung 18. Could channeling be the problem?
Possibly, or maybe broken laterals in the filter. I think it's time for a complete filter breakdown and inspection, and sand cleaning or replacement.
You can read Pamsels other posts in the metals forum, and maybe you have some ideas that can help. Thanks!
Hope this clears things up. It's confused the heck out of me!