Drop in temperature this morning?

[Simon_M]

I run my mixed reef at 25.5 C (actual temperature is normally registering 25.3 C or 25.4 C) down to 23.0 C by accident this morning. So 78 F down to 73.5 F.

I did a 5% partial water change this morning at about 1 am, removing tank water before replacing about 5%. To prevent the ATO triggering, I switched one socket (of 2) off and accidentally switched heater and lights off as well and (worse) until about 9am. I don't like to unplug the ATO DC, so prefer to use the socket. I will switch the heater to the other socket strip and move my UV light onto the socket strip, so that in future it's not the heater that is switched out, btw.

This morning at about 9am, I realised the mistake and switched the socket back on. But, not before tank had dropped to 23.0 C (73.5 F). First time I've done this! It took about 2+ hours to get back to the normal temperature of 25.4 C.

I know that marine fish and corals like stability, hence acclimating fish and corals, but does a gradual decrease (and restoring) temperature have any lasting effects on fish or corals?

Simon

 

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I would assume that it will be fine. Temperatures can change even faster than that in the ocean with tidal swings and cloudy vs sunny times etc.

An extended time could cause issues, or worse a heater stuck on and raising temp high enough to kill animals. But your gradual reduction and return shouldn’t cause a big issue.

 

[Simon_M]

Thinkng about it, the temperature swing with a traditional (bimetallic) heater can be around 2 C, so the change wasn't much outside what might be seen. A digital temperature readout shows the change which ordinarily isn't seen, so seems more than it really is.

I've added some wireless switches - so can now control UV, ATO and Skimmer in addition to Sump Light, Refugium Light and a Room Dehumidifier. In particular, if I want the ATO temporarily off, then there is no opportunity to turn the heater off, accidentally. Happy Days.

Simon