I'm new on pickles fermentation without vinager, last week I put three jars with different recipes I found over internet and it said to leave it outside the refrigerator for one up to four weeks and to check every week. So today I checked for the first time and two out of the three jars the pickles were very soft that I couldn't hold them as they torned apart. The other jar was apparently fine. Can somebody know what happened}? Any advice, thanks in advanced.  Note: I'm located in Mexico and currently the weather is so hot around 90-100 F degrees. 
In addition to Marti's good advice about temperature, I've only had consistent success with Kirby cucumbers, also called (for good reasons) "pickling cucumbers". Raw Kirbies are very firm—even crispy. That lets them stand up to fermentation.    When I first tried pickling, I used slicing and English cucumbers—which left me sad and frustrated. I threw out so many batches for exactly the reason you mention: By the time they sour enough to enjoy, they were too soft to enjoy. They worked now and again, but probably less than 20% of the time.  Many pickle recipes also include one or more ingredients with tannins, which are supposed to help keep pickles firm. I normally used bay leaves. Other examples: black tea leaves, oak leaves, grape leaves,   Only Kirbies consistently give me firm pickles. As Marti mentioned, lower temperatures help too (I try for around 70 degrees); if you have a cellar, that might help. For me, using Kirbies and those cooler temps, 3-5 days yields half-sour pickles and 5-10 yields full sour. 