Salinity and ammonia ??'s

[Retired_AF]

If you have been following my threads you know I just started my first saltwater 90 gallon tank. On Monday I got the water in the tank with a salinity of 1.0245. Tuesday I dosed the tank to 4ppm ammonia. I have had some evaporation and replaced the water lost with RO/DI water. I checked the tank last night and the ammonia was at 1ppm and the salinity has jumped to 1.028.

I know that things are fairly unstable when you start a tank, but this seems a little extreme. Does the ammonia usually disappear that fast? I know I am nowhere close to having the tank cycled but it seems that the ammonia should not have disappeared that quickly.

Also, what could make the salinity jump so high? I havent added anything except RO/DI water to the tank since I dosed it with ammonia.

 

[Qube]

Things do happen that fast. You are going to want to dose to 4 on ammonia and see it converted to nitrate in 24 hours. That's when you know you've developed enough of the beneficial bacteria.

As far as the salinity, did you mix the water first, or did you mix in the tank? It takes a good amount of time for all of the salt to fully dissolve and get into the water. So, if you tested the water shortly after mixing, the salinity could have continued to rise as the rest of the salt dissolved. Just a thought, as I did the same thing when I started out. To drop your salinity now, just siphon out some water and replace with RODI. You're not too far off, so go slowly. Once you get it set, it will remain close to your desired level with the addition of RODI to replace evaporation.

 

[Retired_AF]

I mixed the saltwater in a separate container for 24 hours before putting it in the tank. Since I could only mix 30 gallons at a time it took me over a week to get the water made, mix in the salt and then put it in the tank. I measured the salinity 24 hours after I had it all in the tank (Finished filling on Monday, tested and dosed ammonia on Tuesday, high salinity levels on Thursday).

I suppose I need to take out some saltwater and replace with RO/DI to get the levels down. Dosing the ammonia isnt a problem as I was expecting some drop although I thought this was a lot, but the salinity change caught me off guard. I just dont want to screw this up now. I'm getting too close to being able to add livestock.

 

[Qube]

Do you have a sump set up on this aquarium? What are you using as a gauge for topping off with RODI?

 

[Retired_AF]

I have a 20 gallon sump with a reef octopus skimmer. The water level fluctuates somewhat due to evaporation. I have made marks on the tank return section for the max and min fill lines, the max being the level that would allow the sump to fill without overflowing (about 1" from the top of the sump when the siphoning action stops) if I ever lost power. The min is about 3/4" above the level where the return pump starts sucking air. The return area holds 1-3 gallons while the pump is running normally, minimum of 1 and a maximum 3.

 

[Qube]

Seems as though you got it dialed in then! Strong work! Once you pull out some SW and replace it with RODI, you should be good to go!

 

[Sniperhank]

1.028 is acceptable for salinity, I wouldn't be worried about it. Mine has jumped to 1.031 due to evaporation and there hasn't been any ill effect. I would focus on your cycle and finishing it before even worrying about ph, salinity, or whatever. Just focus on the ammonia, nitrite, and nitrates.