Let us know how that goes! There are two possible causes of tipburn on the indoor lettuce - one as you said, insufficient airflow, but the main problem that I've seen is low relative humidity which causes the leaf to dry out. Using a mister frequently is one way to keep the air moist around the leaves. And not too close to lights. And density can help ie the cut and come style of growing, where moisture is trapped among the leaves and slowly evaporates to keep them humid.
The hydroponic setup is beautiful but you have a lot of air space around each plant, which might contribute to drying out.
OTOH being hydroponic, you would not expect dryness to be an issue. So perhaps the fan will be the answer.