Thank you. I appreciate your precise questions.
It's a new house so I want to install preventively a water filter system:No experience of corrosion yet.
Yes, it's a well water.No idea of the flow rate. Yes, does go into a cistern first which was build as part of my house.
See, sometimes brown sediment in the water. Water does smell a bit.No ,I am not planning to taste the water until I have some
sort of filtering.
Then you need to test your water for the following;
1. Ph. a small swimming pool test kit will surfice.
2. Iron as Fe.
3. Calcium Carbonate. Hardness expressed in GPG (grains per gallon) or PPM (parts per million) either works.
4. Total Dissolved Solids or TDS. This is expressed in PPM or Us/cm Microsiemens per centimeter.
5. Bacteria test. You should be able to take a sample to the Dept. of environmental health to get this done.
You may be able to also get the tests done (except bacteria) from a friend of mine who has a full blown water system in Sosua at his Villas. He is also on this site so maybe he will see this post and chime in.
When drawing water samples, draw them straight from the well and not from the house. run the water for 2-3 minutes from a hose bib (NO HOSE ATTACHED) and simply fill a clean plastic bottle such as an empty water bottle. Don't let the water sit and get the tests done ASAP after taking the samples.
For the Bacteria, you will get the sample bottle from environmental health. Clean the sample port (hose bib) with alcohol using a cotton swab before turning on the water. Then follow the above procedures.
PM me and I will give you my friend's contact information in Sosua. Let me know the results, and we can move on as to how to properly treat it.