Which Algae Feeder to Choose for String Algae?

Ive found cherry shrimp are good at eating SOME algae but not all. What happens for me is they eat up the algae they like (impressive results initially) and then other kinds that they don't like take over. Same thing happens with Amano shrimp. I currently have some kind of branching light green algae, fairly stiff but weak (tears off easily, feels spongy when you squeeze a handfull) that neither cherry or Amano shrimp, ramshorn snails or Ancistrus cats seem to like.

PS - My Vallisneria died back after H2O2 treatment (1 ml/gal daily for 3 days). It resprouted, but new leaves were crinkly and pale for a long time after. My very soft water and inert sand may be a factor.

do you think gambusia affinis might do the same, or are they too carnivorous?

No, I don't think they eat algae. Maybe someone else can confirm.

PS - My Vallisneria died back after H2O2 treatment (1 ml/gal daily for 3 days). It resprouted, but new leaves were crinkly and pale for a long time after. My very soft water and inert sand may be a factor.

Wow, I'm surprised. If I'm doing the math right, that's about 1/3 oz per 10 gallons, no? I usually do 1 oz per 10 gallons. Like I said, I am surprised.