I need help. First time brewing in my life and I made some mistakes as expected. This was a 1 gallon brew kit. First indication something was wrong was after pouring the wort into the 1 gallon fermenter I maybe had half a gallon of actually wort probably due to the boil temperature. I filled with water as necessary. I then attempted to created a blow off tube. I had troubles with the blow off end staying in the bowl and coming out and the end that was in the fermenter was pushed into the beer accidentally. I finally switched to an airlock but the amount of alcohol in the fermenter has vastly decreased to maybe a quarter of a gallon even in there. Can you help with anything or is this too far gone?
If your wort has been reduced in volume due to water boiling off, adding water up to the original volume should not reduce your alcohol level as the amount of fermentable sugars remains the same.
Airlocks vs. blowoff tubes shouldn't be an issue, either. If the level in your fermenter has decreased this can't be due to airlock issues.
So I'm not sure what has gone wrong but I can't see it being related to the issues you mentioned.
This would be a sink special to me, best course of action would be to taste your end product to determine any dramatic flaws in the brewing process. At this time adding water to your brew that is mostly fermented would just dilute the beer. This doesn't mean that it will not be drinkable, just that the ABV will be very very low in terms of a beer, and you may ruin the taste of your first brew by diluting it that much. If you are using a blow off tube, make sure that you have the hose pressed into the bung, it should not be sticking out into the liquid. Another recommendation is to put your sani-bowl for the blow off tube at the same level as the carboy. As for the top off water, if you are using an extract kit, the amount of water you put in is not unreasonable for these kits. To further yourself in the ways of home brewing I highly recommend reading a few books, they are incredibly valuable for beginners. The complete Joy of Home Brewing by Charlie Papazian is one of my favorites. I posted a link to amazon below. As for any issues in the brewing process, it is hard to answer that without more information, it seems more of a mistake with the fermentation vessel and equipment usage in the end. Just remember that every failure is a lesson learned and not a reason to quit brewing. Good luck on the future brews and cheers https://www.amazon.com/Complete-Joy-Homebrewing-Fourth-Revised/dp/0062215752/ref=pd_lpo_sbs_14_t_0?_encoding=UTF8&psc=1&refRID=0CS4M4V3XHQREAN9RJCZ