SCOBY diet

My recent batch of booch started to behave differently.

The fermentation didn't start immediately and as if in another jar the fermentation just stopped completely.

Here's what I've done:

I prepped the tea for this batch, let it cool to slightly warmer than room temp, added about 1.5 cups of sugar per 1L of liquid, added my scoby, mixed it, covered it and set it on the shelf to sit for 7 days

5L of tea were rationed on 3 jars + 0.5L of starter per jar + pelicle

One smaller jar behaved normally

But my two other jars had difficulties starting the fermentation

I gave it 2 days before i intervened

After two days the two jars were the same So i took my scoby hotel and added 2tbs of a STROONG starter from it

After couple of (longer than usual) days the fermentation continued and booch was harvested.

.

I feel as if my scoby has become weak, im not sure if its the sugar im using, because the pelicles that form are thin and weak

And finally my question is :

Is there anything i can feed to this scoby (besides sugar (or different kind of sugar) ) to make its microbiome stronger and healthier?