From what I can gather, you have a pre drilled "reef ready" tank with an overflow box. I made my own durso standpipes for a couple dollars worth of pvc
pipe. You control the water level by the size of the vent in the top cap. Get several caps and experiment with different size holes. You can make the water fall a couple inches which will quiet it down. If you make the hole too small it will "toilet bowl" up and down because of too much suction.
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