Please note that this page is related to my own fish tanks and has been created as an aide memoire purely for myself.
Tap Water Baseline
This is usually rested overnight and maintained at a temperature a couple of degrees below the target tank temperature.
Temp: 23C
TDS: 7
pH: 6.2
KH: 0
GH: 0
NH3: 0
NO2: 0
NO3: 0
As can be appreciated by the above characteristics, the water from my tap is almost akin to RO water. Thus, to make it suitable for the fish that I keep, this water does need to be amended. The main focus points are general hardness (GH), carbonate hardness (KH) and other trace elements to aid plant growth.
GH is a measure of the total concentration of dissolved calcium and magnesium ions in the water column. The reasons for ensuring they are present are:
Essential Minerals for Physiology The calcium and magnesium help fish with osmoregulation (balancing water and salt in their bodies), support heart and nerve function, and build healthy bones and scales
Support for Shrimp and Snails Invertebrates like cherry shrimp and snails require dissolved calcium in the water to properly form and maintain their shells and exoskeletons. A range of 5 to 8 dGH is ideal for them
Nutrient Uptake for Plants The calcium and magnesium help aquatic plants build strong cell walls and activate chlorophyll for photosynthesis. A 5 dGH level gives planted tanks enough minerals for proper nutrient transport without making the water overly hard.
KH is a measure of the total concentration of dissolved carbonate and bicarbonate ions in the water column.
In using Fluval Stratum as part of the tank’s substrate I fell into the Stratum trap. Because Fluval Stratum is an active, buffering substrate, its main job is to actively absorb carbonate hardness (KH) from the water to lock the pH at an acidic level (typically around 6.5). If you have hard water, this is a good thing. However, if like me, you have very soft water this is a bad thing because Stratum’s fondness to absorb KH meant that I could not raise the KH. This in turn prevented me from keeping Neocardina shrimp in my tank
As the Stratum ages, its ability to fight KH dosing will diminish and it is already showing signs of doing so. This leads to an inherent danger that the pH of the tank could swing wildly in the usual diurnal ph shift e.g. at night as carbon dioxide rises the pH could fall dramatically and make the water very acid. Thus KH dosing takes place to address this issue.
To aid the growth of plants, post water change, I also add the appropriate amount of plant fertiliser each week to ensure trace elements for healthy plants exist.
Oase Styleline 175
This is my main tank and is based on an Amazonian biotope. Ahem, apart from Amano shrimp in the clean up crew (CUC)!
Presently, this tank is used as a quarantine tank for any new additions to the main tank. Not that it looks like a typical quarantine tank(!), because I couldn’t help but ‘scape it a bit, which subsequently makes extraction of fish from here to the main tank a tad difficult. Lesson: Don’t ‘scape a quarantine tank…
With the main tank nearing capacity, the future plans for this tank will be to hold SE Asian fish, such as Harlequin Rasbora.
Water Parameters
Temp: 25C
TDS: ~130
pH: 6.4-6.8
KH:<1
GH: 4-6
NH3:0
NO2:0
NO3:<10
Dosing
Obviously, I use the same products for this tank as I do for the main tank. The differences come in terms of lower dosages for a smaller tank.
When you purchase a new aquarium you can not immediately put fish into it. To do so will induce a protracted and cruel death for any livestock.
Instead, you have to cycle your tank, which involves ensuring your aquarium is full of beneficial bacteria (Nitrosomonas) which can break down ammonia/NH3 (generated by fish poo, uneaten food and other detritus) into nitrite/NO2.
Subsequently, other beneficial bacteria (Nitrobacter) can break nitrite down to nitrate/NO3, which isn’t as toxic to fish as the previous two chemicals and can be taken up by plants.
This near-virtuous circle (you’ll probably still have to do water changes to dilute the nitrate build-up) is known as the nitrogen cycle. But to get it up and running takes some patience – up to a month.
I use an aquarium test kit to track the water parameters of my aquarium. The test kit is from NT Labs and it tests for the aforementioned chemicals that make up the nitrogen cycle (ammonia/NH3 > nitrite/NO2 > nitrate/NO3) as well as pH (acidic to alkaline), Carbonate Hardness/KH, and General Hardness/GH.
Living in Glasgow, Scotland means my tap water is very, very soft, with near zero KH and GH. Thus, to provide some buffering in pH swings, I have to add a KH booster (from Arka), and do so up to a value of 3 or 4. For GH I use Seachem Equilibrium
Below you can see a graph of these water parameters, and from mid-October 2025 through to November you can see the nitrogen cycle running its course.
Imbed with custom width & height + Scrolling enabled
The purpose of this post is to document how to optimise a PC to run Assetto Corsa Competizione (ACC) in VR. This is not an out-of-the-box experience, mainly because ACC is based on Unreal Engine, which in itself is not geared towards VR, nor fast action/movement the likes of which a sim requires: ACC proves this point, as did the latest WRC. It’s workable, but it could be better and this post hopes to show how it can be made better.
Note also that it took a long time to gather together all these disparate crumbs of info from all the noise on so many discussion forums, Reddits, Discords, YouTube videos etc, and believe me on the interwebs there is a lot of duff info, extreme views, wrong views, and out-of-date info that is never redacted. And to think AIs base their ramblings on such ramblings… Regardless, where applicable I’ve included links to posts which go into more depth about a particular topic and from which you can glean the necessary background information.
Anyway, I’m starting to use Le Mans Ultimate now, so before I start tweaking that in VR (it’s is not based on Unreal Engine), I thought it best to document how I tweaked my installation to experience ACC in VR at its best.
PC Components
Every PC is different and what options, settings, and tweaks works with one PC will undoubtedly have to be different to take into account the constraints of another PC. Thus, what follows is based on my specs and preferences and, when optimising ACC with VR, your mileage may well differ.
My PC Components
Motherboard: ASRock Z790 PG-ITX/TB4 Mini ITX LGA1700
Storage : Samsung 990 Pro 1 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive
Headset : Meta Quest 3 256Gb
As you can probably appreciate, even with the introduction of the RTX5090 cards, this is a pretty high spec configuration which allows me to play non-VR games in 4K, and affords a good VR experience.
To experience any racing sim at high-ish fidelity through a Meta Quest 3 (MQ3) headset, you should do so over a USB 3 link cable. Playing something slower paced, such as Half Life Alyx, is fine over WIFI, but even with a 6E router I found the bandwidth constraints too much.
The MetaQuest Link app is required to enable the link from within the MQ3 to your PC. This app allows for a few parameters to be tweaked.
Assuming your headset is active, click on the graphic of the device
Under Advanced, select Graphic Preferences
Set the Refresh Rate to 90Hz
Select the Rendering Resolution to 4704 x 2528 (1.3x)
MetaQuest 3 Graphic Preferences
Note these options these represent the best compromise settings when balancing performance of the graphics card, race sim playability and experience/realism, as well as smoothness of in-headset experience.
Oculus Debug Tool
The Oculus Debug Tool allows you to manipulate the settings of a MQ3 headset at a lower level than permitted by the MetaQuest Link app, above. The tool is part of the Oculus PC software and can be found in the installation directory. To locate it, navigate to the Oculus installation folder (usually C:\Program Files\Oculus), then go to Support\oculus-diagnostics. Double-click OculusDebugTool.exe to launch it.
As supplied, the default values are
Oculus Debug Tool Default values
Note: reviewing the above values, Asynchronous Spacewarp is often enabled … at some point!
Essentially what values need to be updated in tool to optimise the MQ3 for ACC are:
Oculus Debug tool settings for ACC
In summary, compared to default values, what has changed and their values are:
Pixels per display pixel override = 0
Force mipmap generation on all layers = On
Offset mipmap bias on all layers = 0
FOV tangent multiplier =0.8 for Horizontal & 0.7 for vertical
Use FOV stencil = Auto
Adaptive GPU performance scale = Default
Asynchronous Spacewarp = Disabled
Video Codec H.264
Encode Resolution Width = 4096 (should be this, not 4064)
Encode bitrate (Mbps) = 950
The biggest gains here are the setting of FOV tangent multiplier. Essentially this is the size of your viewing window and, by reducing the window size, you are reducing how big an area of the simulated world your GPU has to render. However, if you reduce the values too much, you will break the illusion of the simulated world because you will then become aware of that window.
For the values above, if I’m very careful, and press the headset as much to my face as possible (uncomfortably so) and look up/down, I can see the “hard black wall” above/below the viewing window. Remember also that if you were racing one of these cars you would be wearing a helmet so your field of view is naturally restricted, so a black bar simulates that … ? Hmmm
One problem is that some of these settings are lost each time your PC is rebooted. It can be tiresome having to enter these each time ACC is to be played. This is where a batch file helps! The input to the batch file we will call MetaQuest3_ACC_Config.txt and its contents consist of:
service set-pixels-per-display-pixel-override 0
service set-force-mip-gen-on-all-layers true
service set-offset-mip-bias-on-all-layers false
service set-client-fov-tan-angle-multiplier 0.8 0.7
service set-use-fov-stencil true
service enable-adaptive-gpu-perf-scale true
server:asw.Off
The above is the input to the command which will be called from the batch file itself, called MetaQuest3_ACC_Config.bat and its contents are:
START "Oculus Debug Tool CLI" /d "C:\Program Files\Oculus\Support\oculus-diagnostics\" /wait OculusDebugToolCLI.exe -f "<directory of input to batch file>\MetaQuest3_ACC_Config.txt"
EXIT
Nvidia Changes
7th Jan 2026: It’s CES time in Las Vegas and NVidia has announced DLSSv4.5! The upshot of this is that
DLSS Swapper will display the new v310.5 of the DLL (previously v310.3)
NVidia Profile Inspector, can be used to leverage the new Preset M
DLSS 4
Suffice to say that keeping drivers up-to-date on any system is essential maintenance and particularly so for graphics cards. Up until the end of 2024, using DLSS with ACC VR was a bit of a non-starter because it caused a lot of smearing, ghosting and shimmering. The release of DLSS 4 on 30th January 2025 addressed these issues, as well as lowering memory usage by 20% So, if you’re lagging behind with the version of your drivers, rectify that issue now!
DLSS 4 and the following two steps combined were easily the biggest game changers when it came to playing ACC in VR and, for non-VR, provided the biggest FPS gains.
DLSS Swapper
It seems that ACC (and tons of other games) don’t implement the latest DLL as they get released from Nvidia. As a result, ACC implements DLSS DLL version 2.2.15, whereas the latest version is well beyond that – at the time of writing, forty-seven revisions later at v310.3!! Suffice to say, upgrades usually always bring performance and visual upgrades.
Thankfully Nvidia has made these files swappable so if you have the latest DLL you can manually go into your game’s files and swap the old DLL for the new one. However, to make this process less fraught and error prone there are utilities available to ease this process and I’d recommend DLSS Swapper.
Update ACC’s DLSS DLL using DLSS Swapper
The simplicity of this DLSS DLL swapper utility is that it allows you to easily compare before and after scenarios or, if the latest and greatest proves not to be so great, easily back-date to an earlier DLL, or reset it entirely to the original version used by ACC.
Another app which fiddles with NVidia settings at an even lower level is NVidia Profile Inspector. On the GitHub page shown, click Assets and download the zip, extract it and copy the resulting folder to Program Files.
It’s best to read the Related Post linked below, but essentially what’s required is to use the Profiles field to locate ACC. Thereafter, scroll down to the Common section and locate the DLSS – Forced Preset Letter and click the dropdown box next to it. Select Always use latest.
To make this change stick, hit the Apply changes button in the top right corner.
Note that DLSS – Enable DLL Override can be ignored because you’ve already replaced the DLL with the aforementioned DLSS Swapper above.
NVidia Profile Inspector Updates for ACC
Lastly, both DLSS-RR (Ray Reconstruction) and DLSS FG (Frame Generation) are not used in ACC, thus there is no point in applying overrides here.
DLSS Preset Letter
Going back to the point about the DLSS – Forced Preset Letter parameter, if things are not to your liking when Always use latest is employed, I’d say from experience that it’s also worth experimenting with the Preset J.
Remember also that DLSS defaults and presets are subject to change with new versions of DLSS.
Presets are subject to change with each revision, but the following serves as a general guide for experimentations with the current presets:
Presets A – E: Deprecated and will be remove in subsequent releases. Please do not use.
Preset F (intended for Ultra Perf/DLAA modes): The default preset for Ultra Performance mode.
Preset G (Unused): Do not use – reverts to default behavior
Preset H (reserved): Do not use – reverts to default behavior
Preset I (reserved): Do not use – reverts to default behavior
Preset J: Similar to preset K. Preset J might exhibit slightly less ghosting at the cost of extra flickering. Preset K is generally recommended over preset J
Preset K: Default preset for DLAA/Performance/Balanced/Quality modes that is transformer based.
This area is the most subjective and where the most experimentation will have to take place. Whether an option is set to Epic > High > Mid > Low will be very dependant upon your PC’s specification, as well as your own preferences.
With the latter in mind, for example, I prefer to have Contact Shadows enabled otherwise the cars appear to float above the surface of the track and, for me, that detracts from the immersion. However, it is costly in terms of GPU grunt used.
Note that to allow the screen grabs below to be taken, ACC was run in windows mode (as opposed to in VR). Thus options, such as those under Virtual Reality, are displayed below as greyed out, as if not updateable. They will be when the headset is used!
ACC Video Options: Basic Options 1
In the above, not that DLSS Sharpness is disabled. The same applies to other subsequent Sharpness options. This is because a MQ3 performs it’s own sharpening and this was set earlier in the Oculus Debug Tool (Link Sharpening to Quality).
ACC Video Options: Basic Options 2
GPU-wise, I believe that the quality and distance shown in mirrors are the big hitters.
ACC Video Options: Image Customisation
Personally, I don’t like Motion blur and, just to add to my dislike of it, it does incur a large-ish GPU performance overhead.
A decades long ménage à trois of computers, sim racing and F1
My introduction to sim racing started back in the mid 80’s when I had a Sinclair ZX Spectrum and anything related to it and programming was my teenage obsession. I have a vague memory of reading a programming article about coding 3D-esque type games by using parallax scrolling and, due to also being an F1 fan, I subsequently attempted to marry the two interests by writing a racing game using the technique. It kinda worked, but the limitations of the machine’s processing and graphics meant it was relegated to a shelved programming project.
Time moved on, the 80s slipped by, as had my original 16K ZX Spectrum and its wobbly RAMpac, a ZX Spectrum+ replacement, an Amstrad CPC 6128, and an Atari 1040ST. The 90s saw my IT addiction transfigured into a beige PC, initially in the form of an Amstrad PC and then a far better milky white tower system from Gateway 2000, an even better Dell and then Dell laptops proved to be both price attainable and space efficient … though, alongside the hardware, my memory darkens so my timeline might be slipping into the noughties at this latter point.
Anyway, while the IT addition ran amok, the love of F1 hadn’t died and sim racing during the 90’s era of beige meant I played Grand Prix 2. Since my PCs were geared towards the hobbyist spec, and not gaming, a few years later I purchased a Playstation PS1 and Colin McRae Rally – including the purchase of a steering wheel and pedals (serious stuff!) But, despite being seemingly mind-blowing at the time these sims were tame stuff compared to what a sim racer has available to them in the present day.
When I say present day, well more like 2020, at which point I had retired and not played a racing sim in the intervening “serious” years of my IT career. The purchase of a Xbox Series X games console towards the end of 2020, alongside a Xbox Games Pass subscription meant that I discovered Forza Horizon 4. Wow! Okay, it’s more of an arcade-sim but jeez-oh was it addictive. Forza Horizon 5 came along in the spring of 2021 (more wow, more exclamation marks), I also came across Forza Motorsport 7 , and shortly thereafter Forza Motorsport neither of which I was particularly taken by (not so wow, and not serious enough).
Then both Assetto Corsa and Assetto Corsa Competizione caught my eye. I was hooked, I bought a Fanatec wheelbase, steering wheel, and pedals … and then realised that to become more serious I had to buy a PC. Alas, being an IT addict I had to build my gaming PC and spec it with the best in-class components. The story continues…
