Not sure about wicking action of my mix

[ArthurDent004]

I created a self-watering container using two icing buckets from Sam's Club bakery. I used two drain fittings, one for filling the reservior and one for the overflow hole. The overflow is routed to an orange juice bottle.

I have a determinate tomato plant potted in the bucket but I don't think it's getting enough water. The plant looked a little droppy yesterday so I poured four ounces of water at the base of the plant and added 4 ounces of water to the reservior before excess started running into the overflow tube. Before I added to water I put my finger into the soil and it was pretty dry for the first two inches and only slightly damp after that.

I made the potting mix from one brick of mixed coco coir that contain 25 percent pine fines. That came to 2.5 gallons and then I added 2 gallons of perilite. I had seen a video online where someone was making a potting mix using equal parts perilite and vermiculite but I thought the coir would work better than the vermiculite.

I still have a 4 cu foot bag of coarse perilite and coarse vermiculite and four bricks of coir left to use. I'm wondering if I should use two parts coir and 1 part perilite and one part vermiculite for the next bucket or if I should have brought potting mix from Lowes, Home Depot, or a local garden store.