Hi everyone. I'm new here, obviously, and hoping to get some advice/tips for starting over after losing all of my fish. These were actually the 3rd round of fish we've had in this tank over the last 2-ish years. Some background... The tank was a birthday gift for my daughter & we started out with a group of 6 or 7 glo-fish and a pleco. My only prior experience in keeping fish was goldfish I won at the fair as a kid that lived for years with minimal care, so I didn't know about the nitrogen cycle or doing regular water changes or any of that. Despite that, the glo-fish were actually fine for about a year & a half before we started having issues. Shortly before the holidays last year a couple of them died, but we figured we'd had them for a while so it was just their time. We went away for a week & put one of those dissolving vacation feeders into the tank, and when we came back the tank was full of algae and two more glo-fish and the pleco had died, and the remaining two glo-fish were clearly not well. We took them out of the tank to clean it (not knowing any better) and they didn't make it. So - again not knowing any better - we drained the tank, threw out the gravel, cleaned the tank & decorations with bleach water, threw out the filter cartridge, etc. We decided we wanted to try some different fish so we set the tank back up and a couple weeks later went to get fish. At the recommendation of the fish guy at Petco, we got 4 guppies and 3 platys. Things were okay for a few weeks, then one night I watched as 3 fish died one right after the other. Frantic googling of "why are my fish dying" brought me to this site, I read about ammonia poisoning & cycling your tank & all that, so we immediately did a water change and the remaining fish seemed better. I read the articles about the nitrogen cycle and got a test kit & started doing every other day water changes but we still lost all but 1 guppy. We tried to save him, kept doing water changes & testing but I'd misunderstood what I read & thought ammonia, nitrites, & nitrates should all be 0. After another couple weeks we thought the water was fine & our 1 guppy seemed lonely so we bought 3 more guppies, and we've now lost all of them in less than 2 weeks. (We found the last one dead this morning.) SO - now that we have an empty tank again and I've done some more reading and think I understand how to cycle and what the levels should be, I want to do a fishless cycle and really try to do this right. But I have some questions. 1. Should I drain the water that is currently in the tank? Should I clean anything? I don't think any of the fish were diseased but I'm not 100% sure. 2. What's the deal with pH? The last few tests I did it was on the low side (6.2-6.4). Is that bad? How can I control the pH of the water? Is pH as important as ammonia, nitrite, & nitrate levels? 3. We want to try live plants again (had them at first with the glo-fish but they didn't last long). Can I add the plants while I'm trying to establish a nitrogen cycle? Does one affect the other? I'm sure I'll have more questions but this is long enough already, so thank you to anyone who reads this & can offer some advice!