overwatering. Philos drop water when they've had too much, never heard of it coming out of the whole leaf though. I'd be checking and changing the soil ASAP.

I agree with mentha on overwatering. Monsteras do the same thing don't they. It's like the leaves are 'weeping'.

Thanks for your replies.

When you say change the soil do you mean take the plant out of the pot, brush off the wet soil, replace with new dry soil and put it back in the same pot? Or put the whole thing (plant and current soil) in a bigger pot with fresh soil?

And 'moving forward', how much and how often should I water these guys?

Sorry for the questions, I need as much guidance as I can get.

Wash off the roots, wash out the pot, and add new soil along with more perlite. Put it in as small an unglazed clay pot as possible for the root ball. Water deeply, make sure all the soil is wet, allow to drain then put it back, allow the soil to dry until the pot looks pale again. The pot will tell you when you need to water, if it is bright and deep red, it doesn't need watered, when it pales and becomes a dry pot color and the soil is dry for a few inches into the soil, water.

I'd like to add that the color of the pot may or may NOT be an indication of the need to water. Mine don't change color all that much, if at all. Maybe my terracotta containers are thicker or something.

Your plant has been taken out of a great growing environment and into an environment that probably offers MUCH lower light levels. That situation is one of the factors that dictates a need to provide less frequent waterings. The weeping (called guttation) is normal for some plants. In this case it means that there is a lot of water available at the roots.

Thanks for all your replies. I have moved the sick plant, to a sunnier spot.

Needless to say, these guys won't be seeing water for a long time, and won't be seeing that quanity of water ever again.

Can I expect the leaves to uncurl? Will that be an indication that they have recovered, or will they remain as they are even if the plant becomes healthy?

Also, should I wipe down the leaves to remove the excess water?

I can't believe I'm having to ask all these questions- the guy in the shop told me philodendrons were easy!

new and nervous...just to make sure that we're all speaking the same language about the watering. It's important that you water thoroughly when the soil dries out, never in little sips.

Thus, your FREQUENCY of watering will be determined by the plant/soil, but not the amount of water you use each time.