MQLにて動作が軽くなる記述を教えてください（ボタン切替式インジケーター）

前提・実現したいこと

MQL4にてボタンスイッチ式のプログラムを作成しています。
OnCalculateの所にiCustomを使い他インジケーターのデーターを取得し表示・非表示できるボタン作成。

発生している問題・エラーメッセージ

動作が重くなってしまいます。

該当のソースコード

int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
//---
   int limit = rates_total - prev_calculated;
   for(int i=0; i<limit; i++) {
      
     
      //上矢印　MA1:
      MA1[i]=iCustom(_Symbol,0,"Increase",3,60,0,5,70,30,AlertI,false,"Low","High",false,"Low","Low","High","High",20,"チェックポイント★リベンジ",11,clrWhite,C'30,130,151',10,155,clrWhite,C'41,174,204',20,180,bsizex,bsizey,1,i);
      MA2[i]=iCustom(_Symbol,0,"Increase",3,60,0,5,70,30,AlertI,false,"Low","High",false,"Low","Low","High","High",20,"チェックポイント★リベンジ",11,clrWhite,C'30,130,151',10,155,clrWhite,C'41,174,204',20,180,bsizex,bsizey,3,i);
      
      //下矢印
      MA3[i]=iCustom(_Symbol,0,"Increase",3,60,0,5,70,30,AlertI,false,"Low","High",false,"Low","Low","High","High",20,"チェックポイント★リベンジ",11,clrWhite,C'30,130,151',10,155,clrWhite,C'41,174,204',20,180,bsizex,bsizey,0,i);
      MA4[i]=iCustom(_Symbol,0,"Increase",3,60,0,5,70,30,AlertI,false,"Low","High",false,"Low","Low","High","High",20,"チェックポイント★リベンジ",11,clrWhite,C'30,130,151',10,155,clrWhite,C'41,174,204',20,180,bsizex,bsizey,2,i);
                 
      //勝敗
      MA6[i]=iCustom(_Symbol,0,"Increase",3,60,0,5,70,30,AlertI,false,"Low","High",false,"Low","Low","High","High",20,"チェックポイント★リベンジ",11,clrWhite,C'30,130,151',10,155,clrWhite,C'41,174,204',20,180,bsizex,bsizey,4,i);
      MA0[i]=iCustom(_Symbol,0,"Increase",3,60,0,5,70,30,AlertI,false,"Low","High",false,"Low","Low","High","High",20,"チェックポイント★リベンジ",11,clrWhite,C'30,130,151',10,155,clrWhite,C'41,174,204',20,180,bsizex,bsizey,5,i);
      MA5[i]=iCustom(_Symbol,0,"Increase",3,60,0,5,70,30,AlertI,false,"Low","High",false,"Low","Low","High","High",20,"チェックポイント★リベンジ",11,clrWhite,C'30,130,151',10,155,clrWhite,C'41,174,204',20,180,bsizex,bsizey,6,i);
      














//--- return value of prev_calculated for next call
  }
   return(rates_total);
  }