Salinity Question

[James Hammett]

Our tank was at 1.025 on friday. When we returned to school this morning it is at 1.029. ALso the heater i have is a preset heater set at 78 degrees and that is where the tank had been running it is now running at 79 degrees. the only variable is the addition of the Eflux powerhead. I understand how the fan running in the tank could raise temp but why would the salinity jump, and how can i fix it? water change? also seeing a increase in amonia, decrease in nitrites and nitrates are constant at 20.

 

[Flippers4pups]

How do you measure salinity?

 

[EmdeReef]

Do you have an ATO? If not, did you notice water evaporating in the back return pump chamber? That could raise salinity assuming you have an accurate refractometer.
Re. temperature - unless you have a controller, pretty much no heater will keep an accurate temperature (also assuming your thermometer is accurate). You can get a cheap inkbird controller, it's probably one of the best investments to make ensuring that the tank won't overheat.

 

[Luno]

What emd said, heater thermostats are unreliable to say the least, some heaters like an eheim jager do have an adjustment for correcting the thermostat to the actual temperature. the other thing is all equipment and lighting will also add some degree of heat.

If you have a fan hooked up it will generally increase the amount of evaporation in the tank. I would suggest that you have an ato if you don't already

 

[James Hammett]

We have a refractometer we use. It was calibrated last week. I can recheck it for accuracy.

 

[James Hammett]

Do you have an ATO? If not, did you notice water evaporating in the back return pump chamber? That could raise salinity assuming you have an accurate refractometer.
Re. temperature - unless you have a controller, pretty much no heater will keep an accurate temperature (also assuming your thermometer is accurate). You can get a cheap inkbird controller, it's probably one of the best investments to make ensuring that the tank won't overheat.

ATO? not sure what that is. The Eflux has a controller it is set to stream. the heater is preset and is just in the tank. Actually Friday the LFS guy told me to unplug it that it was not needed in the bio cube and that temps as low as 73 or 74 degrees were fine?

 

[Luno]

ATO stands for automatic top off, are you manually topping off evaporation than?

 

[EmdeReef]

ATO? not sure what that is. The Eflux has a controller it is set to stream. the heater is preset and is just in the tank. Actually Friday the LFS guy told me to unplug it that it was not needed in the bio cube and that temps as low as 73 or 74 degrees were fine?

73/4 would be ok but is on the lower end of the ideal temps so temp dipping further would likely cause stress if over a longer period. Also, without a heater you introduce potential for temp swings which are generally more stressful. I have a biocube and even though my ambient temperature is pretty stable I do notice my controller turning on the heater so I would definitely keep a heater on.

 

[James Hammett]

ATO stands for automatic top off, are you manually topping off evaporation than?

yep I am an idiot... LOL
I never considered evaporation what a teacher I am ..... I assume I should top of evaporation with just RO water without salt. I will be doing that manually.
great teaching moment for my kiddos I guess. If only from a standpoint of paying attention and thinking all things through.

 

[James Hammett]

73/4 would be ok but is on the lower end of the ideal temps so temp dipping further would likely cause stress if over a longer period. Also, without a heater you introduce potential for temp swings which are generally more stressful. I have a biocube and even though my ambient temperature is pretty stable I do notice my controller turning on the heater so I would definitely keep a heater on.

Thanks I think i will price a controller for some of these things especially since the tank js in a classroom and may go 48 hours at times without being monitored

 

[Luno]

yep I am an idiot... LOL
I never considered evaporation what a teacher I am ..... I assume I should top of evaporation with just RO water without salt. I will be doing that manually.
great teaching moment for my kiddos I guess. If only from a standpoint of paying attention and thinking all things through.

lol I was about to just suggest are you forgetting about evaporation. It's fine though don't be hard on yourself I had the same moment years ago when I first started. Water evaporates, salt does not. So the salt concentration will increase. Have a look out for an ato particularly if the tank is in a classroom over multiple days without being there to manually top it up.

 

[Idoc]

When water evaporates in your tank... which occurred between Friday to Monday... the water leaves but the salt remains. So now you have less water but the same initial amount of salt, so your salinity will be higher. When toy top off with new freshwater, it now lowers your salinity back where it was before. An ATO automatically puts freshwater back into the aquarium when it evaporates off so that you have a steady water volume, hence a steady salinity. An ATO is a great investment... best thing I added to my tank... just set your water height, keep fresh RODI water in a resevoir, and let it do its thing!

 

[James Hammett]

Thanks, I went just now and added a bit of RO water to the tank will check the Salinity again in say 30 minutes to see where it is. I will look into an ATO and a Controller for the tank.

 

[James Hammett]

its at 1.024 again. I think the evaporation is the key. I will be looking for ways to get an ATO set up now.

 

[liveround69]

i use this setup on my maroon clownfish fry tank. its cheap and works. Its a simple float valve from ebay for around $7 shipped. If you can wait longer then you can order from China for about $1.50 shipped. The ball valve is about $10, and the water line 1/4" OD $7 are both at Lowes or Home Depot. Cheap container for a reservoir from any store $7. Lastly some 2 part epoxy that works on things involving water....easily found in the glue section at the cheapest of stores....even walmart. I also use them in my Reef, FOWLR, and clownfish growout tanks. Never had any problems and great thing is that they dont use electricity like the ones that others were suggesting.