Frequency of water change

[wasabi8888]

Hi all

When I was in planted tanks (CO2 or non-CO2), I usually change water once a week. Now keeping plecos and apistos etc, does the frequency of water matter? Say, one week, i change water once, one week I change water twice, another week I change water 3 times etc. If I can keep Ph rather stable with addition of peat, black water, will I be inducing algae etc?