How to get rid of these red stuff?

[Enigma]

I've got a large patch of cyano in my tank on my sandbed. It started while I was on vacation and was not dosing ZeoBak. It is in quite an open area of my tank, which has moderate flow.

I couldn't get any ZeoBak yesterday (and I'm out), and I couldn't find any Microbacter7 (I know I saw it locally . . . I just can't remember where).

I picked up some of Instant Ocean's "Natural Nitrate Reducer" (a polymer) and "BIO-Spira" (live, nitrifying bacteria) as I felt those could be beneficial in reducing the nutrients and thus the cyano. I dosed 50ml of the nitrate reducer and 20ml of the BIO-Spira to my 55 gallon system last night (shut off the skimmer for two hours afterwards).

This morning, the cyano had reduced by about 50%. Maybe it is just coincidence . . . but I'll be dosing 20ml of the BIO-Spira a day for the next two weeks.