Abyssalite Is great for keeping a cold area cold, or warm area warm, BUT if you take Abyssalite from a warm area, and try to tile a cold area, that Abyssalite will maintain the heat from the area you harvested it.
Airlock Control
You can prevent certain Dupes from using an airlock by clicking it, and choosing access permission.
Base Design
Base design is important. You need enough space in each room for items, and decor, while enough space between rooms to allow for airflow (thus needing less O2 producing items.) Creating a 3 block space between rooms. Room 1 ends, empty tile, ladder, empty tile, room 2. Dupes can jump one space, land on the ladder, and go to the next room. Having a 3 open block space between rooms provides better air flow for Oxygen. - Refer to the Image section below. Algae is Limited Early Game Early game, Algae is limited. Move on to Electrolyzers for O2 until you can SAFETLY enter the Slime biome.
Building Rotation
Certain buildings can be rotated using the O key.
CO2 is heavier than O2
Assuming you have O2 generation in your base, CO2 will sink downward. Create pits toward the bottom of your base for food/CO2 storage.
CO2 is Sterile
Food does not rot in a sterile environment. If you place your Rations Box fully submerged in CO2, the food inside of it will not rot.
Don't kill Hatch's
Seriously, don't kill them. This one was embarrassing as hell. I had no clue that they make coal. Coal is used for power generation a few cycles in via Coal Generator. If you build a storage compartment near them, and fill it with dirt; you can feed them to keep making you coal. If you have all tile underneath them, the Hatch's never go to sleep.
Food / Item Transfers
If you set your new Rations Box/Storage Container to Priority 6, and a different one has a lower Priority, your Dupes will automatically transfer the items in them.
Food Management
If you set your Rations Box to Priority 6, when you dig up food while exploring, your Dupes will automatically bring it to the box. This also applies to food that has been harvested, and cooked.
Food Priorities
So my Dupes would always eat Meallice, and I could never make bars. I had no clue that you can set your Dupes to not eat certain foods. Color me stupid.
Population Control
You can reject taking on new Duplicants. You should NOT take more than 6-8 until your colony is fully stablized.
Slime Biome
Do not rush into the Slime Biome. Slimelung can seriously mess you up if you're not careful. Make sure you've multiple airlocks, wash basins, and ore scrubber setup before entering one. Limit how many of your Dupes enter at a time.
Such as airlocks!
Airlocks can be rotated to be up-down rather than left-right!
Valves
I'll get straight to the point. It took me a long time to figure out what valves were good for, or even what they did in ONI. Obviously, they allow gas and liquid flow only one way, do not require power, etc. But recently, I discovered a way they can be used to more efficiently spread the flow of such resources through your colony.
The process is actually really simple. All you need to do is hook, say, a liquid valve up to your main water pipe that goes to your Lavatories and Sinks. However, do not have the flow output of the valve running to your toilets; instead, hook the input to the pipe itself, and leave the output somewhere off to the side. This may seem counter-intuitive, but what this does is it causes part of the water flow to be siphoned off from the pipe, and sent to the output.
I used this to solve the issue of how I was unhappy with my main water pipe just stopping after it flowed to the toilets, and me not wanting to snake it all the way back around to my Carbon Skimmer in my coal-fired power plant area. Instead, I installed a valve on the pipe near my water cistern, and bam! Water just flowed through the output at an easily settable rate, plenty and to spare to run the skimmer all cycle long. And all this without interrupting the flow of water to my bathrooms at all; all I did was 'borrow' some water from the pipe, since the bathrooms didn't need so much anyhow. This prevented me from having to build a whole new length of liquid piping, or even a new liquid pump entirely, as I could now much more efficiently use the water I had already available.
There! Now you are armed with the knowledge of precisely what valves do. I wrote this short guide because I was unsatisfied with what the tool-tips told me; if I'd known before they could essentially siphon off pipe flows, I would have used them a LOT sooner, as adding in valves makes my colony feel a lot more clean and efficient with its resources.
