Hemp Goddess, there are a lot of unknowns here, but one thing that isn't an unknown, is that supplying that reservoir with that cooler's output, is the least energy efficient method you can come up with, dear.
It isn't known if the swamp cooler's big enough to do the job on the room.
It is known, that the ventilation isn't sufficient for whatever cooler is in place, because in a properly deployed cooler, the water in it's reservoir gets c o l d - NOT hot.
It reaches a temperature called the 'wet bulb' temperature, and that temperature is defined as the coldest you can get an object, by getting it wet, and blowing air over it, evaporating off the water: in this case that 'object' is the reservoir of water in a swamp cooler.
First start proper ventilation. If the cooler can keep the room properly cool, when properly deployed, fine.
Of course properly deployed means, drawing dry air in from out of that room, and never letting it slow down, venting it out: not letting it hang out and re-dump it's thermal load back onto the solid objects in the room.
The humidity and the temperature are two different subjects: and, a properly deployed swamp cooler can only give you about a 45% or 50% humidity out the front: there are reasons, i'm not gonna go into it;
If you have a properly deployed swamp cooler, and you desire a 'higher than 45 or 50%' relative humidity, at that point you'll need to get one of those misters they sell for patios, etc, and deploy that in the room. It's deployment is it's own subject.
But the cooler dear, is not a good idea. That, being central to the question, i will address.
Firstly you'll have to dump not only the heat of running the compressor, but the heat off the water out of the ground, that it cools: somewhere. Secondly unless the water out of the compressor is in a very well insulated tubing, which i do not doubt you could do - it will absorb heat from the surrounding air before it even makes it to the swamp cooler: and it'll be a net gain of very small advantage: since 1/4 inch tube is usually black it'll try to absorb heat- hard. The tubing would need to be short: and well insulated.
Even then, you're not gonna be able to achieve good results: because of the nature of the problem at hand, and the nature of a compressor style water cooler.
I wish you good luck, and it would be nice to know: the size of the fan on the swamp cooler, the size of the room; the number of light watts, and where you're drawing the air from, for the swamp cooler; also, the quantity of air out: if that water is getting hot, it's obvious there's very little air out, for the room.
The swamp cooler properly deployed, whether it's big enough to cool the room or not, will never give a relative humidity out of it's front face, over about 45 or so percent. In order for the cooler to be run at max efficiency, you have to have dry air in, and equal air out of the room, not re-using the air.
If you use a mister system, it will function as a cooling unit, on it's own: but you will need to deploy properly and very skillfully to avoid mold issues with one; what you really need is a big-enough swamp cooler, and some skillful mister deployment.
The mister deployment needed to achieve proper 70 % humidities, and not by the nature of how it's done, create a mold likelihood, would be a separate issue, unto itself.
Good luck Hemp Goddess
