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Nitrate filter for tap water


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So I’ve tried multiple different things for the nitrate issues I have. My tap water comes out at 25 ppm nitrate. Looking at the US map seems like a lot of us might have this issue. Oh, to live in a green area!




I’ve tried algae scrubbers, anoxic filters, submerged plants, terrestrial planets (pothos), purigen, and matrix.


I’ve used nitrate selective resins in the tank which work great, but I really wanted something to filter the incoming water. I tried a DIY filter for the tap water using the loose resin (below) but didn’t get good contact time to filter the nitrates down to where I wanted. It’s also expensive (although I found at a deep discount!) and I didn’t want to foul it using it in the tank or in a dirty canister.




I’m sure there’s something else I’ve tried that I just don’t remember.


This is what I finally found that works best for my situation. I bought a 4” x 10” nitrate specific filter to pre-filter my tapwater. This is how I built it for aquarium use.


First you need a Pentek big blue filter housing. Mine was $25 on Amazon. I got the one with 1 inch NPT connectors.




I also bought a pair of 1 inch NPT to garden hose adapters.




I use Rectoseal to make sure I have a good seal for the threads.




The filter is this Intelifil brand. It is about $76. Not cheap, but fortunately rechargeable (they don’t tell you that, but it can be done... see below). It can run at up to 2 gpm which for me is just below full blast out of my faucet. This is compared to 0.5 gpm of most RO units.




I connect my python faucet adapter to a short segment garden reel leader hose (female to female)




Screw that into this filter and then plug my long garden hose that goes to the tank into the other end.


I use a lot of quick connects on my python so I also use these on the filter and hoses. When I’m storing the filter I bought a pair of hose caps to close it off.




I use these nitrate test strips to test the water. I will even cut these in half to get more uses out of the bottle.




How long this will filter the water of nitrate depends on the nitrate concentration of your water. The filter states it filters up to 12,000 ppm. I could not find out if this was PPM as nitrate–N, nitrate or nitrites as CaCO3. Anyway, I generally test the water after every 2-300 gallons. The nitrate concentration in my water does fluctuate.


When the filter is no longer significantly reducing the nitrate concentration I regenerate it using a 10% brine solution. This is a little over 4 pounds (4.2 to be exact) of salt in 5 gallons of water. I use water softener solar salt which is about $6 for 40 pounds.




I mix up the brine and pump it through the filter using a small water pump (158 gph from Harbor Freight) set on its lowest setting aiming for 2gpm or less. I connect this pump to a piece of 1/2 inch hose to which I added a female garden hose adapter to connect to the filter.




I actually use the pump to move the water to dissolve the salt too (because that is a lot of salt). After I run that through I will flush with another 5 gallons of fresh water. Then it’s ready for its next use!


In total this cost about $130 for everything, but I did have some of these pieces already. It is still cheaper than an RO unit and allows you to use your faucet rather than doing a slow RO water collection requiring storage.


You can also daisy chain these big blue filter units together if you want a carbon filter or something else in front of it.







Sent from my iPhone using Tapatalk


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