Hi, and welcome to the forum!

Ben is really the only one around here with commercial pool experience that can help when you start discussing how to chlorinate without tabs. If he hasn't checked in here by then, I'll shoot him an email and ask him to take a look at this post.

In answer to your question, there are cal-hypo tabs that do not contain stabilizer, but the ones on the market now are junk--get mushy and completely dissolve way too fast to be used as a feed system. Besides, the chemical reaction that occurs when they break down provides quite a bit of heat and makes them unsafe to use in a closed feeder. It would also be a real mistake to use them in a feeder that previously used trichlor, because explosions can result when those two are mixed. There are also lithium tabs, but they are extremely expensive and would not be suitable at all for a commercial pool, simply due to the cost. I don't even know if they would work in a feeder for a pool that size.

So...the short answer to your question is that there are other tab forms that are not stabilized, but none that would work for your situation.

Sorry, I know that's not the answer your were hoping for!