Vegetable plants turning yellow and leaves dying
I planted my first garden this year and was really excited about how well it was doing. We have a raised bed that I've planted cucumbers, tomatoes, green and red peppers, green beans, and snap peas. Everything was doing great for about a month after transplanting them when then I started noticing yellow specks on my cucumbers. When I looked closer my tomatoes had yellow specks also (they were much smaller though). Now almost all my plants are yellowing in some aspect. My peppers leaves are yellowing at tips of leaves. My peas leaves are mostly light yellow but new growth are green. And my cucumbers and tomatoes are still suffering from yellow spots. Cucumber spots have gotten larger, but the tomato plants are just getting a few whole yellow leaves that die. I had been watering with 1/4- 1/2 strength aquarium water that's had no chemicals or anything added to it. Then I had crumbled egg shells into like a powder at base of plant. Also added a little epsom salt around base of plants when symptoms started.the ph is between 6-7. I haven't tested nutrient levels but plan on doing that this weekend. I thought maybe the bed wasn't draining well and that it was roots, but after pulling a few plants out in fear of disease, I saw that roots were perfectly healthy. Any ideas on what would cause all plants to show symptoms? Any help would be greatly appreciated.