I just looked at your new pics and you have a slight heat issue and a pH problem, or toxic soil problem. Those lower single tip leave that are turning yellow is normal because those are only used when the plant first germinates and is a seedling. Just make sure you didn't add too much pH up or down, or adding anything meant to "keep your plants healthy" like H202 or other products that may contain ingredients that dont have to be on the label but are potentially lethal to Mary J plants and your plants should have no problems.
EDIT: I just looked at your photos again, your plants are being poisoned by something and it is too hot .(Probably your pH adjustment chemicals or water source) There was a kid on here i helped that had similar looking plants, that burn on the edges ins't nute burn, thats toxic chemical burn. This kid was using 3% hydrogen peroxide thinking it would keep his plants healthy. It did but at the same time he didn't know the 3% H2O2 had added chemicals in it that are there to keep the peroxide suspended and help aid in cleaning wounds. The h202 he was using was not food grade or better so he was essentially poisoning his plants. he flushed out his roots and stopped using it and his plants came right back. Everyone else had a million ideas from nute deficiencies, to pH, to heat, humidity, calcium deficiencies, note lockout, etc.
Also, you said you are distilling you water by letting it sit for 24 hours, this would remove the calcium from your tap water as well if you are distilling it correctly. If you are not adding it back in then there is a likely hood that yes you may have calcium deficiency as well but does't look like it to me. It's up to you to figure it out. This is all i can think of that you should have to check out and experiment yourself.
Also just buy a $20 brita filter (or cheaper brand), it makes the water a lot safer for you and your plants. Unfortunately, toxic chemicals are legal to be in water sources as long as the concentration isn't that high. F that, what happens as they build up in your body over time and you get sick. Spend the $20 for peace of mind. It's like smoking half the amount you do for 2 days, not that big of deal.