$HistoryLength = 0;
ic = 50;
i = Table[2500*j, {j, ic}];
n = {200};
r = 1000;
KSTL = Table[0, {j, ic}];
Do[
 j = 1;
 Print["i=" <> ToString[i[[j]]] <> " r=" <> ToString[k] <>
   " Memory= " <> ToString[MemoryInUse[]]];

 str = OpenRead[
   "/home/someone/somewhere/results_r1000/fi_
i_" <> ToString[i[[j]]] <> "_n_" <> ToString[n[[1]]] <> "_r_" <>
    ToString[k - 1] <> ".txt"];
 dis = ReadList[str, Number];
 mu = Mean[dis];
 sigma = StandardDeviation[dis];
 re = If[KolmogorovSmirnovTest[dis,
 NormalDistribution[mu, sigma], "ShortTestConclusion"] ==
"Do not reject", 1, 0];
 KSTL[[j]] = KSTL[[j]] + re;
 Remove[dis];
 Close[str];
 , {j, ic}, {k, r}]

i=2500 r=1 Memory= 75359488

KolmogorovSmirnovTest::ties: Ties exist in the data and will be     ignored for the KolmogorovSmirnov test, which assumes unique values.

i=2500 r=2 Memory= 118608248

KolmogorovSmirnovTest::ties: Ties exist in the data and will be ignored for the KolmogorovSmirnov test, which assumes unique values.

Remove::remal: Symbol Removed[dis] already removed.

i=2500 r=3 Memory= 118716136

Remove::remal: Symbol Removed[dis] already removed.

i=2500 r=4 Memory= 118738672

KolmogorovSmirnovTest::ties: Ties exist in the data and will be ignored for the KolmogorovSmirnov test, which assumes unique values.

General::stop: Further output of KolmogorovSmirnovTest::ties will be suppressed during this calculation.

Remove::remal: Symbol Removed[dis] already removed.

General::stop: Further output of Remove::remal will be suppressed during this calculation.

i=2500 r=5 Memory= 118762120

i=2500 r=6 Memory= 118784760

i=2500 r=7 Memory= 118806984

i=2500 r=8 Memory= 118829208

...

i=2500 r=44 Memory= 119643952

i=2500 r=45 Memory= 119666488

i=2500 r=46 Memory= 119689024

i=2500 r=47 Memory= 119711560