# Something is Living in my Pool-Cooled Gaming PC Source: https://www.youtube.com/watch?v=fFtk9gJLnfk Recap page: https://rapidrecap.app/video/fFtk9gJLnfk Generated: 2025-11-06T19:02:38.076+00:00 --- ## Quick Overview The attempt to use pool water to cool a high-performance server rack failed catastrophically due to corrosion caused by the pool's chemical composition, necessitating a complete shutdown, disassembly, cleaning of the heavily corroded water blocks, replacement of filters, and a re-evaluation of the cooling loop's fluid choice to prevent future biological growth and corrosion. **Key Points:** - The initial pool water cooling attempt resulted in severe corrosion, evidenced by green/yellowish buildup and gunk inside the CPU and GPU water blocks. - The corrosion was identified as copper corrosion, likely caused by the pool's chemical additives, which were not suitable for the cooling loop. - The team had to completely drain the system, remove all computers from the rack, and clean the components, including scrubbing the water blocks with a toothbrush. - The corroded CPU block showed significant buildup, while the GPU block from another system was even worse, revealing copper corrosion. - The team discovered the pool water lacked essential biocides/antimicrobials, leading to organic growth (slime/gunk) in the system, particularly visible in the reservoirs. - The UV sterilizer, intended to kill microbes, was only effective against UV-C light, which was not what the current setup was emitting, highlighting a mismatch in protective measures. - The final plan involved replacing the corroded components, installing new 10-micron filters, and using proper coolant additives (like silver coils) to prevent future issues. ![Screenshot at 02:21: The host examines the highly corroded CPU block, revealing significant yellow/green buildup in the microfins, confirming the corrosive effects of the pool water on the copper components.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-02-21.png) **Context:** This video follows up on a previous ambitious project where the creators decided to cool their entire home server room using a pool as the ultimate heat sink. After initially running the system, they encountered significant problems related to the pool water being used as the coolant, specifically corrosion and biological growth within the water blocks and filters, prompting a major teardown and cleaning operation. ## Detailed Analysis The video documents the aftermath and repair process following the decision to use pool water to cool a server rack system. The initial test resulted in significant corrosion and organic buildup, forcing a complete system shutdown. The team disassembled the liquid-cooled components, revealing severe damage; the CPU block showed green/yellow corrosion, and the GPU block was even worse, exhibiting heavy copper corrosion. They also found slime/gunk in the reservoirs, indicating biological growth due to the lack of proper biocides in the pool water. The initial plan to use a UV sterilizer was found to be inadequate as the light spectrum used was not sufficient to kill all pathogens. The repair involved draining the entire system, cleaning all water blocks, replacing heavily fouled 10-micron filters with new ones, and reassembling with proper coolant, including an antimicrobial silver coil. The host noted that the flow paths in one of the water blocks were installed incorrectly (inlet/outlet reversed from the optimal configuration), which may have contributed to the issue, but the primary failure was the corrosive nature of the pool water itself. ### System Failure Diagnosis - Water from the pool caused severe copper corrosion and biological growth (slime/gunk) in the CPU and GPU water blocks, visible after disassembly (02:21, 06:01). ### Water Treatment Issue - The pool water lacked necessary antimicrobial properties, leading to growth; the installed UV sterilizer was ineffective because it lacked the correct UV-C light spectrum needed for full disinfection (12:13). ### Repair Steps - The team drained the system, removed all servers, cleaned the components (including scrubbing water blocks with a toothbrush, 06:08), replaced the dirty 10-micron filters (03:39), and planned to use proper coolant additives like silver coils (02:29). ### Component Inspection - The CPU block showed corrosion, and the GPU block from another system was even worse; one water block was also found to have its inlet/outlet fittings reversed from the optimal flow path (06:54, 07:29). ### Conclusion and Future Plan - Despite the setback, the components were salvaged, and the team planned to use proper, clean coolant and re-test the system, noting the importance of correct flow orientation (11:42) and regular filter changes (03:38). ![Screenshot at 00:05: The host standing next to the pink server rack, introducing the massive system that relies on water cooling.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-00-05.png) ![Screenshot at 00:03: A dramatic shot of a computer tower being dropped into a pool, illustrating the extreme nature of the cooling concept.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-00-03.png) ![Screenshot at 02:21: The host dressed as a pirate, holding a small treasure chest containing the silver coil additive, used to prevent microbial growth.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-02-21.png) ![Screenshot at 03:40: Close-up of the heavily fouled, greenish-brown filter cartridge removed from the water system.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-03-40.png) ![Screenshot at 06:01: Extreme close-up of the corroded CPU water block showing heavy yellow/green buildup in the microfins.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-06-01.png) ![Screenshot at 07:17: The host showing the CPU water block top piece, pointing out the flow direction markings \(In/Out\) that were incorrectly assembled on one component.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-07-17.png) ![Screenshot at 02:59: The host pointing out the complex red PEX plumbing manifold used to route coolant to various components and reservoirs.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-02-59.png) ![Screenshot at 11:15: The host and another team member working on the exposed server internals, dealing with complex wiring and water fittings.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-11-15.png) ![Screenshot at 13:36: The host showing the new, clean white 10-micron filter next to the heavily soiled, greenish filter, emphasizing the need for routine maintenance.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-13-36.png) ![Screenshot at 17:28: Two weeks later, the host checks the reservoir controller, which displays '00H', indicating the UV sterilizer was running for 12 hours \(12H\) on one reservoir but zero hours on the other.](https://ss.rapidrecap.app/screens/fFtk9gJLnfk/00-17-28.png)