- Joined
- Sep 21, 2018
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I just started using the Hanna Marine Nitrate Checker and liked every step of the procedure except one: filtration. No matter what I did, nothing stopped the occasional, seemingly random leaking. The “autopsy” I performed after each leaky filtration provided me with no insight into the leak. So, this morning after dealing with another leak, I decided to take a closer look at the filter which is beautifully made but failing all the same.
The filter is sealed when the top cover containing the silicon gasket is screwed down, pressing the soft gasket over the raised lip that forms the outer edge of the seat for the filter disk. Simple. It should work, but I saw imperfections on this raised edge that could conceivably allow liquid to squeeze under the gasket and follow the channel created by the less than smooth surface. I used 800 grit emory cloth and a circular motion to slowly sand down the sharp edge to a wider flat surface. After several sanding and pressure testing cycles, the seal was perfect. I made the seal so good that in my last pressure test of the syringe, I managed to blow off the top of the filter without any leaks prior to the catastrophic failure. Luckily, the filter was not ruined.
The filter is sealed when the top cover containing the silicon gasket is screwed down, pressing the soft gasket over the raised lip that forms the outer edge of the seat for the filter disk. Simple. It should work, but I saw imperfections on this raised edge that could conceivably allow liquid to squeeze under the gasket and follow the channel created by the less than smooth surface. I used 800 grit emory cloth and a circular motion to slowly sand down the sharp edge to a wider flat surface. After several sanding and pressure testing cycles, the seal was perfect. I made the seal so good that in my last pressure test of the syringe, I managed to blow off the top of the filter without any leaks prior to the catastrophic failure. Luckily, the filter was not ruined.