Sounds like spider mite. These plants are extremely susceptible to them. Look at the leaves near the stem and hold them up to a window to back light the leaves. See very tiny spider webs between the leave where they sprout from the frond stem? I have around 8 of these plants. Some came with the house and are now seven years old... Since they came to my care. I love them. Our home is plantation style... But up north! These palms add to the plantation feel in the summer outdoors. They do fine all summer. Then I need to bring them indoors for the Michigan hard winter. It is a real trick to keep one alive for 6mo indoors. Especially if bringing in from outdoors. I have nearly lost everyone of them and I don't typically spray until I see signs and then the damage is clear.... Still my treatment has saved them all so far. To solve the problem... Spider mite and or scale. Majesty palms are very susceptible to both. Bring it outside or to the garge if you can. Take a ounce of malathion and add to a quart of water. Mix and add to a sprayer. Now bathe, soak... tops and bottoms of the plant fronds. If indoors, you should do this at least lightly every two months. I soak them good in the fall with the mixture. Then I mist them while in the house every 2 months or so. I still will get mites and yellow leaves because I often don't treat until I see yellowing, it's hard to over or underwater them. They're hardy to both, though they prefer moist... Not soggy soill. So water lightly more often than a soaking every three days. They also like a mulchy soil. Add shredded back or even saw dust! The bugs love them! Keep the malathion handy if you own this plant. They originate from river banks in Madagascar, so they are use to damp, but not soaked soil. These are the only plants that I bring indoors over the winter, because up here big ones run 80... To 150.00 each. I've been forced to become a bit of an expert on this one plant type.

Have you tried miracle gro ? I would try that as its more balanced and it should have magnesium in it. Make sure your soil is not old and don't keep it soaked but moist all the time. You can mist the fronds three times a week or more to that will help. Sometimes you have to remove some of the soil and replace with fresh and a peat/perilite mix is ok.

Been doing Mexican palms near pools for 18 years. I would say 7 is safe. Planting the palms too far from pool looses its look and I believe is not needed to be so far away. Roots grow mostly downward and across approx. 7 feet. so that is 3'.5" - 4' feet in each direction from center of trunk, giving extra few feet of room/space between pool wall and roots. Water Mexican palm tree with more water to get it close to desired height, then cut back water and will grow much slower. Rick

If you're using a chunky, porous, airy soil, root rot is not a concern. MG potting soil is known for its' predominance of tiny particles, which take forever to dry out. This is what overwatering means but it's not your fault. It's the soil holding too much moisture, so the problem is really underdrying. If there are no tiny particles in a pot, it will dry soooo much faster. People who lose plants because they forget to water would have a hard time with this, (and nothing to fix except to try to remember to water a little more often,) but if you're the more common 'overwatering' type, this can mean the difference between plants that stay alive vs. those that die. I used to kill plants by 'overwatering' too until learning how to fix things through the great info here at GW. Roots can't survive sitting in soggy, dense, airless soil. To fix that, we need to give them something much more chunky, porous, airy. Many address the problem by adding a significant amount of perlite to bagged potting soils, but that's still not idea because the tiny particles are still there, with no air between them. Ideally, the tiny particles should not be in a pot at all. Dealing with it by 'not overwatering' is done successfully by millions of people, but those who like to water plants often are just going to kill them without a great mix of no tiny particles. Most plants can survive getting too dry once in a while. OTOH, getting soppy wet too often and taking forever to dry out is fatal to most. I might recommend an alternative source of water other than tap water, such as rain, melted snow, condensate from dehumidifier or A/C, distilled. It makes a huge difference if tap water is making a plant visibly ill (which it usually does over time.) Yellow, chlorotic leaves are not attractive. Another good thing about parlor palms is that they will put up with about any indoor conditions that humans can tolerate and are very long-lived plants. This info may be helpful.