Where can I find a weatherproof dimmer switch for my outdoor pond pump....yes it is variable speed.

All electric motors run hot and pool pumps are no different. But how hot is too hot for a pool pump? The first test is simply whether you can touch the motor or not. Under normal operating conditions, the motor end of the pump is hot enough that you can barely touch it - but not searing hot.

Best to you.

https://www.google.com/search?q=XtremepowerUS+2HP+In-Ground+Swimming+Pool+Pump+Variable+Speed+running+temp&newwindow=1&sxsrf=AB5stBhpriuNhnfXLYYTg7tuS-LWwW262g%3A1690815381903&source=hp&ei=lcvHZKH_NOHi9AOquJjADw&iflsig=AD69kcEAAAAAZMfZpVdAAi94QXZiwKfN3nArsWv-Gm1z&ved=0ahUKEwjhnd6RmrmAAxVhMX0KHSocBvgQ4dUDCAo&uact=5&oq=XtremepowerUS+2HP+In-Ground+Swimming+Pool+Pump+Variable+Speed+running+temp&gs_lp=Egdnd3Mtd2l6IkpYdHJlbWVwb3dlclVTIDJIUCBJbi1Hcm91bmQgU3dpbW1pbmcgUG9vbCBQdW1wIFZhcmlhYmxlIFNwZWVkIHJ1bm5pbmcgdGVtcEgAUABYAHAAeACQAQCYAQCgAQCqAQC4AQPIAQD4AQL4AQE&sclient=gws-wiz#kpvalbx=_sMvHZMuPJPez0PEP3M2LgAY_44

R22= 70-80psig
R410a=120-130psig
Depending on many variables such as blower speed, coils clean, indoor/outdoor temps.

Yes and no. Waterfalls in outdoor ponds do providecirculation by moving the water around and keeping it from becomingstagnant. This does however, create acurrent which is not always ideal when trying to grow plants or if you arehousing small fish in your aquarium. Astrong current can make it difficult for plants to take root and can be tootiring for small fish to succeed in.

No, there are two issues:

1) There isn't a good way to wire the dimmer to the fan without simulatenously wiring it to the other components within the humidifier - dimming electronics that are not designed to be dimmed is just asking for trouble.
2) The problem with fans is that they can lock up - and when they do, they can pull an excessive amount of current out of whatever switch/dimmer is controlling it. The devices need to be rated to handle that excessive in-rush, and it would annihalate a basic rotary dimmer.

If this is 220v then your netural is not a netural but a common. Meaning it is common 110v to both the high and low speeds of pump. The high and low speed are the same leg of the 220v or the other 110v leg they just separate at the clock or high/ low switch. Then yes they run through separate windings for high and low.
If your not getting high speed it could be the high speed winding but be sure to check your switch and high speed lead first before doing anything else.

Yes a 30mA RCD is required for any 240v outdoor use. Check if there is an RCD on the house main switch breaker first tho'.

change out your switch and it should be ok; if it worked in the past. when a dimmer acts like this there is no fixing them they need replaced

Are you saying you have a dimmer for the fan light and it does not work, or you do not know if the fan came with a dimmer switch?
Most of these fans have two switches; one is for the fan speed(usually three speed) and the other is for the lights(on -off). Adding a Remote control , which is optional for this unit , will allow for remote speed control(variable or three speed), and light dimmer control. The remote controls can be purchased in your local Home Depot or Lowes store. Hope this helps....

Check the strainer at the pond. Prime the pump and see if it pumps anything.

A regular dimmer switch will not do what you want.  A variable speed switch similar to a dimmer but made specifically to control motor loads may do what you want.  I think it would have to be installed after the 5-speed controller because the reduced voltage may cause problems for that controller.  Maybe you should just replace the controller with a the variable speed switch.