KyleH
Guest
Could it be your skimmer / top off?
Hello zeek,
I have a far fetch thought about your salinity. It is highly unusual that your water is getting "sweeter" that quickly.
You mentioned that you had a 46 gal. Perhaps there is about a total of 30 gallons of saltwater, and I was wondering if your skimmer is just pumping out 1/2 cup of saltwater each day, and your top off is putting ro/di (or freshwater) back into the system. That may be the case especially if the skimmer gunk is clear like water.
I am making a far-fetch guess, but 1/2 cup of freshwater can drop your salinity by 0.0001. So, maybe 10 days later, it could drop it down a full 0.001? And weekly water changes may not raise it back up completely unless you are using "saltier" water. So, after 3 or 4 weeks, it could explain the low number. Same idea can apply to your ph, too.
Can you turn off your top-off system for 1-2 days to check to see if there is a leak? With it off, it can give you an idea if your top off system is putting too much freshwater into the system. I should hope you would notice a puddle of saltwater, but maybe you have a drainage setup. Maybe feel around the carpet around the tank to see if it is wet/moist or a strange build up of dried up salt crystals. If you leak a 1 drop a second, carpetted areas may dry up before the area is noticeably wet and your top off can easily put that back as freshwater.
(Haha...maybe you got a fish, or clam, that like to spit out water? How about that day you got back from the frag swap. Did you drip acclimate each one? Did the top-off refill freshwater to replace the water that was dripped out? Did you leave the drip running? Is it still running in a sink/puddle still?)
In most cases, people's tank gets "saltier" or higher salinity from the evaporated water. Adding unnecessary freshwater or "sweet" water is what I suspect when salinity drops.
(I personally use oceanic floating hydrometer for their nano tanks. It is an intank small 1.5" x 2" hydrometer/floater that you can always eyeball it. I put mind on the side out of the main view and also in low flow. I like it because it is not big or bulky; rather, it is kind small and not visually obtrusive. You can get it from PETCO for $10, or online for $8. My stomatella snails freak me out from time-to-time when they hide and play in it. But, I also have a refractometer to double check any off readings. I use it as an early warning device, but I does bob up and down bec of my flow--so, I usually take an everage of the high and low readings.)
-KyleH
Hello zeek,
I have a far fetch thought about your salinity. It is highly unusual that your water is getting "sweeter" that quickly.
You mentioned that you had a 46 gal. Perhaps there is about a total of 30 gallons of saltwater, and I was wondering if your skimmer is just pumping out 1/2 cup of saltwater each day, and your top off is putting ro/di (or freshwater) back into the system. That may be the case especially if the skimmer gunk is clear like water.
I am making a far-fetch guess, but 1/2 cup of freshwater can drop your salinity by 0.0001. So, maybe 10 days later, it could drop it down a full 0.001? And weekly water changes may not raise it back up completely unless you are using "saltier" water. So, after 3 or 4 weeks, it could explain the low number. Same idea can apply to your ph, too.
Can you turn off your top-off system for 1-2 days to check to see if there is a leak? With it off, it can give you an idea if your top off system is putting too much freshwater into the system. I should hope you would notice a puddle of saltwater, but maybe you have a drainage setup. Maybe feel around the carpet around the tank to see if it is wet/moist or a strange build up of dried up salt crystals. If you leak a 1 drop a second, carpetted areas may dry up before the area is noticeably wet and your top off can easily put that back as freshwater.
(Haha...maybe you got a fish, or clam, that like to spit out water? How about that day you got back from the frag swap. Did you drip acclimate each one? Did the top-off refill freshwater to replace the water that was dripped out? Did you leave the drip running? Is it still running in a sink/puddle still?)
In most cases, people's tank gets "saltier" or higher salinity from the evaporated water. Adding unnecessary freshwater or "sweet" water is what I suspect when salinity drops.
(I personally use oceanic floating hydrometer for their nano tanks. It is an intank small 1.5" x 2" hydrometer/floater that you can always eyeball it. I put mind on the side out of the main view and also in low flow. I like it because it is not big or bulky; rather, it is kind small and not visually obtrusive. You can get it from PETCO for $10, or online for $8. My stomatella snails freak me out from time-to-time when they hide and play in it. But, I also have a refractometer to double check any off readings. I use it as an early warning device, but I does bob up and down bec of my flow--so, I usually take an everage of the high and low readings.)
-KyleH
and I also have slowed down my skimmer. 
