What type waterer are you using? How old are your birds? What greeds? Are you sure they died from not havin water? How are the other birds actin? How hot is it where you live? Do they have access to cool, shade, dust baths etc?
The reason i ask is this... we decided we wanted use nipple waterers. So when the chicks were bout a week old we made them... liter soda bottles with screw on nipple tops. We left in the reg drinker we had been usin to make sure they were gettin water still while they learned to use the nipple waterers. Two days later the chicks were peckin the heck out of the new bottles.. but the bottles were still full to the gills. So what we didn't think about was the vacuum.... and it not lettin water flow from the nipples. Once we poked holes in the liter bottle all was fine amd the chicks all started usin the nipple waterers just fine. So we knew to make a largeish hole in the lid of the five gallon nipple water bucket we made when we sized up.
Eta.. i see the watereer you are usin... is the hole that is on the bottom side of the bottle open? It is only a small hole and that is fine. Do not make it larger! Are you puttin the hole on the lowest side how it sits? It should run out and if put the hole on the low side the tray it won't keep overflowing. Did you take that black cap that is coverin the hole at the bottom of the bottle off and screw it up on that nub thinger that is higher on the bottle? The nub thinger is there so you dont lose the cap. The cap is used for when you are filling the bottle so it doesnt all run out. But when you get the bottle situated in the tray you need take it off the bottom nub and put it on the higher nub. Then it should work right....
Here is a video showin how do it....
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