iSpring FD15 DeIonization Replacement Filter Fit RO/DI Water Filter System for Aquarium, 10" x 2.5", 1 Count

Ispring customer service is awesome. They always have a live knowledge person to assist you. I installed this filter in addition to my ispring R.O. System. Lowered well water tds from 600+ down to 1.

Nick from the customer service department quickly responded to some questions and solved issues I was having with my system on the spot. The first reply I received was a direct solution. Not only him, but this is the second time I've contacted customer support at iSpring for a variety of issues and they've always been exceedingly pleasing. May the forces that be give the man a bonus, raise, because he made a lifelong customer outta me.Thanks for the wonderful customer experience.Now, on the system: it's main use was for drinking, cooking and miscellaneous cleaning around the house. However, I've caught a bug and now use it for all my fish tanks. It's perfect for aquarium use, grows great plants, and will filter my pH=8,dgH=0, dkH=14, TDS=300PPM water to 0ppm and undetectable level of Mg, Ca, and CaCO3. If aquarium is what you want, you've found your product.

Working great so far and yielding 0 ppm. Connected to the output of an RO system. Had it for several weeks and I see little or no color change. But I haven't tried replacing the resin yet.Didn't come with fittings which is annoying, but fortunately I had fittings from another DI filter that didn't work. Standard RO system 1/4" tube fittings work. You want the fittings that are threaded on one side to fit a cartridge. You can insert a 1/4" bare tube, even one that you cut, and tighten. Then screw that into this cartridge.Update: After a year it was putting out 22 ppm (30 ppm in from RO). Next time maybe I'll replace after 6 months. Opening and refilling it was easy. Opening took some oomph, but I didn't need a tool. Due to all the 1 star reviews about breaking it, I didn't tighten it very much when reclosing. Only snug. I don't think this little force could ever break anything. Even so it is leak free. You may want a tool to open it, but when you close it please just do hand tight and don't muscle it. Or you might be the next 1 star reviewer who broke your filter.

iSpring Water Systems provides a great group of products. Don Huie has provided me with stellar customer service like I rarely encounter when I purchase products. I have been a user for several years in my home. I have the maximum number of filters in my system, plus a uV light. I have a parts per million (ppm) meter installed inline just before the faucet to dispense. It reads 0 to 2 ppm, when before the system it read 227 ppm. The water tastes so much better, but most importantly is just healthier. I am a Public Health masters candidate in college and the quality of the air where you live, inside your house and the especially the water that you drink is critical to good health by eliminating toxins that attack your body and create inflammation in you entire body systems that result in disease. iSpring and Don have been a constant in my family for over 15 years.

This item doesn't come with the instruction how to use it properly and what it should to use for. When I read on the description of this item on Amazon.com, it didn't say anything about how it is safe for drinking water. I have a RO tankless system, it only read 15PPM after installation. After installation with this DI (FD15) filter cartridge, it only read at 0PPM! It's taste fine, but I read on iSpring's website that stated it's NOT RECOMMENDED for drinking water! Nick, customer service sent me a different filter cartridge (model: FA15).Thank you Nick, for helping me out about the right filter.

So I added this filter as the final stage of my RO system and it worked great. Super easy to install. Brought my TDS down to zero and didn't lower my pH. Only thing was that it did lower the water pressure a bit. A couple weeks after installation I noticed the fish odor in my cups and it drove me crazy as was trying to figure out why it smelled. I later realized the fish odor was in the filtered water. I even called my water company to report the smell but they said it's the filter for sure because tap water didn't have the odor. After researching what could be the cause, I removed this filter and sure enough smell gone. Glad I didn't go through the trouble of changing the carbon filters, that was my first thought but I just replaced them a month ago when I added the DI.I did read another review suggesting I place the alkaline filter after this one, but I'm too scared to try that. Especially since my pH wasn't affected to begin with. I couldn't stand the fish odor and it was only getting worse as time went on.I also read another review stating this filter is for aquariums and Ispring will send the correct filter. The description of the product does specify for aquarium, now, not sure if it did at the time I purchased it. I called Ispring and left a message, haven't heard back from them. Can't find another DI filter under their brand.