Instead of looking for a cleanup crew to take care of it, why not look for the cause of it?
What Makes Red Slime Algae Grow?
Nutrients that come in the form of nitrates, which are produced from DOCs (Dissolved Organic Compounds).
DOCs are produced from excess broken down organics, such as from detritus, uneaten foods, and decomposing plant and animal matter.
Phosphates and silicates are other nutrient sources to take into consideration.
Providing too much or the wrong spectrum of light. It seems that red slime algae grows best in the 555-564 nm (manometer) wavelength.
Solutions?
Start with one solution and see what results you get, and if that one doesn't work, try another one, and so on, until the problem is resolved.
Adjust or change the type and/or duration of light being provided.
Red slime algae prefers the low water flow areas in an aquarium. These low flow or calmer water areas are prime spots for it to get started and take hold. Improve aquarium water circulation by adding a powerhead or two, depending on the size of the aquarium, or a wavemaker or surge device.
Eliminate the algae's food supply by controlling DOCs, nitrates, phosphates and/or silicates. The most effective way to get rid of excess nutrients is to reduce the cause of them. This can be accomplished by cutting back on feedings, siphon up detritus and uneaten foods off the bottom of the tank regularly, and by adding a protein skimmer.
You can try using an additive to "cure" the problem, such as with Aquarium Instruments Ultralife Red Algae Remover as one example. However, many of these types of treatments appear to only solve the "symptom" (red slime algae) of an underlying problem. Cyanobacteria are a form of bacteria, and many of the additives currently in use are antibiotics, which are medications that can weaken or totally wipe out the biological filter base of an aquarium. Use these types of treatments cautiously!
Luckily, this algae does not attach well and can be siphoned out of the aquarium to help prevent the spread of this nuisance, while you determine and correct the cause of the problem.
Just another case of cut and paste
Thomas