Yes. If you haven't already figured this out, there are numbers of how-to-do-it posts here starting with the "Featured Answer" at the top of this thread. Because Houzz displays only part of the Featured Answer, you want to click on the faint "read more" line to get Houzz to display the rest of that detailed post by Luna123456. Also, there are something like 1.1k additional posts in this thread, most of which are not initially displayed. On my computer, I have to display all the posts before I can do a full search of the thread. Houzz makes you look below the "Featured Answer" to find the fine print which currently reads "see 1037 more comments." You may have to click a "See more comments" several times to get Houzz to display all of the posts. Then you can do a terms search (CTRL-F calls up a search box on MS Windows computers.) That will get you the posts with recommendations on specific brands of detergents and oxy liquids to use with DIY refilling.

@silveretta Zone 6a MA You can safely ignore the TwinDOS reminder to use it or run a maintenance cycle. It really only matters if the system has not been used for a long time, like months. Push the OK button when the warning comes on the screen and it will be dismissed. Enable the option to remember the last used settings. It is called "Memory" under settings. Then if you turn TwinDOS off it will remember that on subsequent cycles. You will have to remember to turn it back on if you want to use it. I have that option enabled and when others use the washer they sometimes forget to turn it on if it was off. It is possible to turn twinDos off all together in the service menu, but that really should not be needed. For the water intake fault there are usually two reasons for this. One is there is crud stuck in the little screen filter in the water supply hose. There is a little screen in each end of the water supply hose. Designed to catch big pieces of crud before they enter the washer. Crud can slow the water flow and cause the intake fault warning. The other cause is low water pressure. If you have low water pressure and the tub does not fill quickly enough that can trip the intake fault as well. There is an option under settings called low water pressure. If you enable that the machine will allow for a longer fill time. While it is possible to have a faulty part, it would be very unlikely on a newish machine. To test and see if the suds are from your clothes go buy a BRAND NEW towel from the store. You need one anyway right? Turn off TwinDOS and use no detergent. Run the towel on rinse and spin cycle (under more programs). Observe if there are any suds. If there are no suds then you have confirmed there is detergent build up in your other clothes. If there are minor suds then these can be caused by simple air bubbles in the water. Make a note of how many there are and that is your normal "Clean" water. Another way to test is to fill a cup or glass jar half full of water, seal it and then shake it up for 30 seconds or minute. Note how many suds, if any, are produced. This will give you an idea of how many suds are generated in your "normal" clean water. Once you have a known clean towel you can run a few cycles. Bump the Dose for agent 1 up in 5ML increments. You will know when you have reached the correct amount for your water when the water rinses clean, but you have suds during the main wash. You can always go a little over and then back off when you notice more than your "normal" amount of suds in the last rinse. Citric acid would be un-needed if you have really soft water. Its main use is to remove built up mineral scale from the outer drum, heating element and any parts and hoses wash liquor is circulated through. If you have really soft water or a water softener then there is no mineral scale to build up. Even in REALLY hard water areas you should not have a ton of mineral scale inside the washer as long as your detergent is dosing properly. The detergent has water softening agents. As long as the right dose is used any minerals will be bound up and go down the drain. It is also not possible for the TwinDOS detergent to leak into the washer. The bottles are located below the lowest part of the drum. They are pumped into the drum at the correct time and in the proper dose. Dose is determined from the amount of time the pump runs. The pumps have a known amount that they dispense each minute. So if you set a particular dose the pump is run for the amount of time to deliver that dose. See the video below for a quick overview of how it works:

My WWH860 was updated by the app about two weeks ago. I never had the problem with the prewash so I wasn't sure why. I did have to rerun the Calibration program. What I noticed after? Water plus no longer automatically appears in the app as an Extra. There is less water in every fill in every program. I had previously entered the programming menu and set water plus to one water drop a few months before the update, so I went back into that menu and reset it to one drop, afterward not much difference in the water level. I entered the menu again and set the level to 2 drops. There might be a bit more water but it is hard to notice. Still less water in the machine than before the update. I've turned auto-update off. From now on if nothing is wrong I don't want any updates.

First trial went well. Shoe care guide said come water only. So used delicates mode with cold. Then used the TRK555 dryer basket also on delicate mode. Looking good.