Do I really need to buy?

[reefwars]

Again as your not seeing the picture and yes I would agree that smaller more consistent water changes are better then less frequent water changes but that's not what I'm saying ....water changes are a poor way to export nutrients ....all you've done is diluted a small amount of nutrients that will likely be replaced and then some by next week's small dilution , I'll get you something in return once I'm not on my phone but the idea of all this IS NOT to remove nitrates and phosphates it's more to export the build up of metals and replace elements ....the removal of nutrients is a small bonus bot the sole purpose ; )