Selling Water

Ad Astra Unlimited Strategy Guide: Operation Aquarius
So, you might've realized that you need more than just food to eat, you also need to supply your martian with water. Thankfully, Mars isn't completely devoid of water on its surface, unlike Phobos.
These strategy guides may not be completely accurate on their ROI due to fluctuations based on how stamina works, marketplace fees, and other variables, take this more as a general guide than exact numbers.
To gather Water, we will need a Water Filter. We're going to buy an Gen II Uncommon Water Filter, this building turns Ice into Water. Let's look at the Player Guide for the Water Filter to find the loot tables.
40 Ice
16 Water (100%)
10 Power
4 Regolith (100%)
1 Stamina
Not too bad, the Uncommon Water Filter at level 1 also has 5 Task slots. So we can set up 5 of these tasks at a time. Let's look at the important values.
Ad Astra accountants would like to remind you that values are at the time of writing (2/28/2022), not financial advice and not guaranteed. We'll throw a rock at Phobos if ROI is not found.
Value (Dusk)
Full Power Cell
Empty Power Cell
Uncommon Water Filter Gen II
Common Land Plot
For this strategy, just like our one about selling gas, we'll be buying Full Power Cells and selling the empty ones after.
How much would it cost to start filtering? Assuming we're filling up all 5 Tasks slots it would cost us 11 Dusk:
Water Filtering Cost
Ice (200 @ 40 per task)
6 Dusk
Power (2.5 Power Cells, 10 Power per task) Note: We're selling the Empty Power Cells back, functionally making each power cell cost only 2 Dusk
5 Dusk
Now what do we get back in return? Well, looking back at the first table we'll receive 16 Water and 4 Regolith multiplied by 5 (for the task slots). Which is 16 Dusk worth of Water and 0.4 Dusk worth of Regolith. Not bad! This gives us a profit of 5.4 Dusk.
Now each of these cycles takes 6 hours, how long would it take for us to make back an ROI?
Time to make back Dusk
Uncommon Water Filter
111 Hours (4 Days)
Common Land Plot
1,666 Hours (69 Days)
Now, that's just using one Uncommon Water Filter. Let's go ahead and buy five more since our Common Land Plot still has 85 space left. Now how much Dusk do we make?
Time to make back Dusk
Uncommon Water Filter
111 Hours (4 Days)
Common Land Plot
332 Hours (14 Days)
With six total Uncommon Water Filters on our plot, we'll be making a total of 32.4 Dusk per six hours, or 129.6 Dusk per day. This is just with level 1 Gen II Uncommon Water Filters.