Fluval Flex Aquarium Filter Mod

myminifactory

After buying a Fluval Flex 35l/9g, I noticed some flaws and opportunities to tinker. So, I redesigned the system and added new features. This is Part 2 of the project, which covers cooling, heating, light control, water refill, and other ideas using an ESP micro controller without destructive modifications to the tank hardware. The original filter has a strange arrangement of filter media. Generally, you want water to flow through mechanical filtering first, then biological, and sometimes chemical (like active carbon treatment or nitrate removal). In the original setup, water was routed more or less through the mechanical filter, maybe touching the biological or chemical one. I designed an insert instead of the original sponge block that can take three separate baskets and ensures a top-to-bottom flow direction. At my current setup, the middle basket is filled with EHEIM substrate pro, the upper one with a piece I cut out of the original sponge, and the space above the upper basket is loosely stuffed with filter wool. For me, it now works perfectly fine, and the EHEIM substrate outperforms the original Fluval bio filter by a lot. Nitrite is always below 0.2mg/l (ppm). The models should be printed in the orientation of the STLs (maybe rotating the case 90° around Z). All models can be printed without support. The baskets can be printed without support, assuming your filament profiles are dialed in well. The bridge length is 20mm. Otherwise, please use supports. Print: Please use the files for your tank: _57 for the 57l/13g and _35 for the 35l/9g. 1x Case 1x Handle 3x Basket Pay attention to insert the baskets with the small holes facing towards the open side of the case. The Case is inserted into the tank with the intake holes to the left (standing in front of the tank) - not the side where the pump is. Use PETG, PA, or any other food-safe material and water the model for at least 24h before inserting it into the tank. If you plan to switch to other bio filter media, insert it in the lower basket and the used one in the one above. Leave this for at least 4 weeks before removing the old one. A huge thank you to Trigg-Darren for providing the dimensions of the 57L and testing! Published project parts so far: Fluval Flex Aquarium Filter Mod - https://www.myminifactory.com/object/3d-print-95120 Suction cup mount for DS18B20/DS18S20 temperature sensors (Aquarium) - https://www.myminifactory.com/object/3d-print-95606