Water change Question: Max acceptable temp difference/change.

[Patrick Whitehead]

I'm new to Marine tanks but have been keeping freshwater off and on since the late 60's. My last experience was with planted freshwater. (CO2 injection, dosing ferts and the like). There I got away with some pretty wide ranging differences in temperatures with my water changes. I know with marine systems the tolerances are tighter.

Don't have the tank yet; still doing research. I'll be mixing at a station in my garage which can get a little hot (mid to high 90's are not unheard of). I'm planning the basic 10% per week so a temp difference in the makeup water of 10° would show up as a 1° change in the final temp in the tank.

What is a tolerable difference before I float an ice bag or something?

 

[mcarroll]

If the water is at one of the temperature extremes, just make sure you stick with small water changes and you shouldn't have to worry.

But if it comes up, I wouldn't purposefully drop the DISPLAY TEMP any more than 2-3 degrees.

I'd hope that's in the sump too, so there's a lot of mixing with display water vs one big shock. You can definitely get away with a larger temperature differetial in the sump.

IMO corals and fish seem to appreciate the "rainfall effect". Temperature does drop on reefs due to rain/storms.

 

[Crabs McJones]

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I would agree with what @mcarroll said above. No more than a 2 to 3 degree temp swing and add the new water into the sump so it has more time to mix in with your tank water instead of dropping or raising the display tank temp by adding it up top

 

[Patrick Whitehead]

Thanks for the quick replies. So little to worry about till the garage gets over 100° or so. That'll work fine.

 

[scott11106]

if you are mixing the water and doing a 10% change you will be fine as long as you are not mixing and leaving the water in the heat for an extended amount of time as the water will be colder from the well/city and by the let the water mix. you could always add a wall ac unit or a fan directed at water to use for those times but i dont think it is needed.

 

[Patrick Whitehead]

I'll be setting up an RO/DI unit. It'll probably have enough time to come to a higher temp. Add to that 24 hrs of aging/decanting time after mixing. I plan to have one reservoir for RO/DI water and another for mixing, both covered. Would there be a problem with letting a pre-mixed batch sit for up to a week; maybe two? I know there may be some re-mixing to insure proper parameters but is there any danger of the mix going bad for any reason?

 

[lapin]

Would there be a problem with letting a pre-mixed batch sit for up to a week; maybe two? I know there may be some re-mixing to insure proper parameters but is there any danger of the mix going bad for any reason?

It wont go "bad". You will lose some of the advantages of a water change. Example ; Alk will change over time, as CO2 creeps in. And to quote Randy "abiotic precipitation of calcium carbonate can occur". You will want to mix it again before adding it to your tank.

 

[scott11106]

if you have a power head in the salt mix it will be fine for that time, it does not have to run all the time, for instance i have 55 gallons of salt mix and i have a pump come on every 4 hours for 15 min and that keeps everything mixing and fresh. it lasts me almost two weeks before i have to make a new batch

 

[Patrick Whitehead]

It wont go "bad". You will lose some of the advantages of a water change. Example ; Alk will change over time, as CO2 creeps in. And to quote Randy "abiotic precipitation of calcium carbonate can occur". You will want to mix it again before adding it to your tank.

Thanks, ya'll are great at response turn around.

As per advice I gleaned from my research I'll check pH,Salinity, and Alk just prior to the water change and adjust as needed.

if you have a power head in the salt mix it will be fine for that time, it does not have to run all the time, for instance i have 55 gallons of salt mix and i have a pump come on every 4 hours for 15 min and that keeps everything mixing and fresh. it lasts me almost two weeks before i have to make a new batch

What timer do you use?

 

[scott11106]

Thanks, ya'll are great at response turn around.

As per advice I gleaned from my research I'll check pH,Salinity, and Alk just prior to the water change and adjust as needed.



What timer do you use?

i actually use an APEX controller and have the pump on the eb832, if you keep the water moving and use it under 2 weeks i dont think you will need to test your salt mix.