general question about water change

[Guava Jelly]

I'm setting up a more automatic water change system. the question is: for a 100 gallons of water (90 for the tank and 10 for sump), if I'm doing a 20 gallon water change, should I have the water heated to temp? i'm guessing yes, but just want to make sure. thanks ahead of time..

 

[doma25]

what is the room temperature of where the water is sitting? Not sure how temperature affects water chemistry and how quickly salt dissolves but you should be fine without heating it

Also, it depends on what corals/fish/inverts you have and how sensitive they are. Id say over 5 degrees in water temperature change can upset the more vulnerable aquarium creatures. If you have hardy fish like clowns id be less worried. Your fish tank heater will probably heat the water up quickly too.

If your tank is 100 gallons and you change 20 gallons... assuming the 80 gallons is at 78 degrees and the new 20 gallons is 60 degrees - that will make your new temp around 74 degrees.... 4 degree drop

if you do 20% of 50 degree water then the water would be around 72 degrees. 6 degree drop

So all in all if you are changing just 20% or less then as long as the water is above 50 degrees you're probably fine.

 

[Guava Jelly]

thorough and makes a lot of sense. I appreciate that much. I will definately keep an eye out for room temp. I will mostly do 10 gallon water changes but on the occasion that i do more I'll take this into account.

 

[Timbo]

A gradual change in water temperature is not a huge cause for concern within a safe range but a sudden drop by adding water not heated to temperature is not worth the risk imo. Also will depend on what you keep in your tank and what results you are looking for. Adding a small heater to your set up sounds like an inexpensive investment for a smaller water change.

 

[Josh]

If the temp of the water is close to 70, and the tank is roughly 80, then try to add the water over the course of 30 minutes. Your heater should be able to keep up with that.

 

[Salted]

Warming your water change water will help to dissolve the salt both more quickly and thoroughly. A basic 150w heater like an eheim jager is about $25. That and an el cheapo $10-$20 amazon powerhead and water mixing is faster and easier. Bonus now you're got a spare heater on hand for your tank should the need arise.

 

[Guava Jelly]

all good advice. thanks. I have the pump already. will get heater