Auto Top off incident need a question answered

[digital_dragon]

Last night I was moving my sump light and did not realize that it had caught on the wiring going from the autotop off controller and the float switch. I walked to the kitchen to get something and found my water level in my sump had raised 2 inches and thought something was going screwy with my pump. Upon inspection I saw where my float switch level had been raised two inches and the auto top off system dumped 2.5 to 3 gallons of fresh RO into the tank. It dropped my SG from 35 PPT to 33 PPT. I have since turned off the auto top off system until evaporation can do its job and return my SG back to 36 PPT where it stay rock solid until something like this happens.

My question is, What are the effects of the sudden drop in SG to my tank and can this drop although temporary for a 24 hour period until evaporation does it's thing kill off anything in my tank or is it not a significant enough drop to really affect anything other than making the inhabitants mad.

Any input or answers are greatly appreciated to assuage any fears that I have of my tank crashing because of this fresh water dump.

Earl

[Geoff]

i can not remember what you have in the tank. any fish would prolly not even notice. soft corals or anything that is truely water based, LPS may be annoyed, but i would think they will come back if the return is gradual. i may be a little worried about pods and other small microfauna. if they make it throught the initial drop then they i would think they would be fine.

i can not remember the implode-explode salinity thing right now, but i think lowering the SG causes small critters to explode. hence the FW baths to kill parasites. absolutely chime in if i am wrong.

my .02 guess $

G~

[digital_dragon]

I have 6 Peppermint shrimp and 3 Skunk Cleaner shrimp. Various mushrooms, Yellow Polyps, Button Polyps, Pulsing Xenia, and Blue Anthelia. I am most worried about my shrimp. I checked the tank this morning before work today and they were all accounted for and I will check back in on them at lunch and see what the status of things are I just hate the wait and see what dies thing.

Earl

[Doug1]

Earl I don't think 2 pts is gonna be that bad, it will prolly take 2 days evep to get back to normal. If nothings showing a major freak out yet you are prolly OK, I hope

[David Grigor]

I wouldn't worry too much about it.

Once I took my float valve off becuase was sticking. Since the sump level was low I left the 1/4" tubing in the sump to fill it up while soaking the valve ( top off water was a 55g plastic drum ). Needless to say I forgot about it and went to bed. Woke up about 4:00Am and suddenly remembered. Tank is 190g+60g sump. Salinity dropped from 1.025 down to 1.017 in about 7 hours time and did not suffer in any losses with over 200 corals mostly sps in the tank. Brought it up to 1.020 in a couple of hours then gradually brought it back to 1.025 in a weeks time. Achilles & Hippo tangs showed some ick from the stress but were strong and healthy enough to fight it off within a couple weeks with garlic added to the food.....

[digital_dragon]

David, Doug, and Geoff,

Thank you for your posts I checked the tank during lunch and no casualties so I will the the water evaporate off slowly until it returns to my normal SG. I have since moved the controller for the float switch lower to give more slack on the wires as to not have this happen again. It is always something with this hobby I guess that is how we learn. Thank you again guys for your help.

Earl

[galleon]

Organisms can take a sudden drop much better than they can take a sudden spike. You should be fine, just let the salinity go up by evaporation.

[Geoff]

Originally posted by galleon
Organisms can take a sudden drop much better than they can take a sudden spike. You should be fine, just let the salinity go up by evaporation.

why are FW baths used for parasite infestations instead of hypersalinity baths. curiosity question.

G~

[MikeS]

I've had several experiences similar to this when I've forgotten to disconnect the auto top off when doing a water change. While I've also worried about it, I've never seen any damage.

[digital_dragon]

Geoff,

FW Dips are RO Water with 0.0 Salinity. Flatworms or Black Ich (which is a flatworm) need salinity to equalize their bodys internal turgor or equalibrium. When you do a freshwater dip your taking the parasites normal equalibrium in a specific Salinity and putting it into an environment that has nothing equalizing the outside of the parasites body so their internal pressure causes them to explode and melt. I have tested this with flatworms and it is pretty darn cool. I hope I explained it right.

Earl

[Geoff]

digital_dragon-i got the reasoning behind why the little buggers go pop. i was just wondering why galleon thinks it is easier for organisms to handle a sudden SG drop(FW bath) then a sudden SG rise (Hypersalinity bath). is it just easier for us to execute than a Hypersalinity bath or is there another reason i am missing.

G~