First timer, funky SG readings

[Luke]

Yesterday i mixed sea water, and a few hours later got an SG reading of 1.024.
I wanted to go get Live Rock and Substrate today, but checked the SG again before leaving for the LFS, and found my SG to be 1.032. I've drained two o fthe the 6 gallons from the tank, and now get an SG reading of about 1.023... just under 32 ppt on the other scale. What is going on?

 

[Luke]

The water in the tank is giving me a reading of 1.023 right now. The water i drained from the tank is way higher.....air bubbles???

I smacked the crap out of the hydrometer with a pencil to dislodge air bubbles. What do i do?

 

[Innovator]

What do you do? Buy a refractometer, they are more precise. Until then, make sure there aren't any air bubbles in the hydrometer. If you can, it is best to let the water mix overnight, around 15hrs-24hrs.

 

[ccCapt]

In addition to the above, a hydrometer is also dependent on the water temp. As the temp gets higher or lower, the SG reading on the hydrometer can change.

 

[Luke]

Well, the water in the tank is 78 degrees, The thermometer says so, plus that's the only setting the heater i use has. I measured the SG in the tank, and got a high reading. So i drained some water, and took another reading, and it was normal, but when i checked the water i drained, it was high again. The only thing i can think of is that i had air bubbles in my hydrometer. I will let it sit another hour or two, and take another reading. If it comes out normal, i will go ahead with the live rock and agronite.

Cycle:
Internet sources suggest the shrimp method. However, the book i have says since i will be using fully cured live rock, all i need to do it check the ammonia and nitrate levels for three days, if i get three zeros, i can begin to stock the tank...
Anything?

 

[melosu58]

If you can get fully cured LR then you`ll probably skip the cycle or only have just a mini sike at the most. The problem is making sure it` s cured LR. Some LFS will put it in a tank for a day and say it`s cured when it`s not. You`ll be able to tell with your water tests kit.

 

[austinsdad]

Get an ammonia and nitrite test kit and check ASAP.

 

[Kurt_Nelson]

And even with cured live rock, throwing a shrimp in is a good thing - just to make sure it's truly cured. If it is, you shouldn't see any ammonia/nitrites... or very little... and nitrates should start showing up quickly. Better to find out before adding any critters!

 

[Luke]

Put a raw shrimp in with the live rock a few hours after adding the rock to the tank.

Last night
Ammonia:0.5 ppm
PH:8.2
Nitrite:No change in sample
Alkalinity: Normal-high range
SG: Swing arm needle just under the 1.023 mark
I did not check nitrate levels.

Today
Ammonia: 1.0 ppm
Nitrite: 0.5->1 color range
Nitrate: 20ppm
PH: 8.2
SG: 1.0225 (Needle dead center between 1.022 and 1.023 marks.)

It would appear that i have the proper bacteria in my system.
Could salt creep be the culprit for my slight drop in salinity? I have some pre-mixed water on stand by. Should i consider adding a minute amount to my tank to bing it back up?

 

[Kurt_Nelson]

...

It would appear that i have the proper bacteria in my system.

Actually, no... it doesn't. Looks like the normal beginning of a cycle. If you had a good population of bacteria you wouldn't see any ammonia or nitrites.

Could salt creep be the culprit for my slight drop in salinity? I have some pre-mixed water on stand by. Should i consider adding a minute amount to my tank to bing it back up?

I'd say the hydrometer is the culprit for the drop in salinity.

I wouldn't worry about the salinity right now. Looks like you're going to have a few weeks while the tank cycles and at the end you should do a massive water change to lower the nitrates. At that point, you can adjust your salinity as required.

 

[thincat]

In your first post you said "you mixed saltwater". Are you mixing it in your Aquarium or in a seperate bucket then adding it to your tank?

 

[Luke]

I mixed it in the tank, brand new and had the power head running in with it for two days before i did anything else. After i was satisfied that it was circulated enough i drained about half of it out and added live rock and aragonite. When i was done with that i replaced some of what i drained out to top it off and started to cycle it.
To clarify, No i am not mixing it in the tank anymore. Just when i first got it and it had nothing in it.

 

[Luke]

Actually, no... it doesn't. Looks like the normal beginning of a cycle. If you had a good population of bacteria you wouldn't see any ammonia or nitrites.



I'd say the hydrometer is the culprit for the drop in salinity.

I wouldn't worry about the salinity right now. Looks like you're going to have a few weeks while the tank cycles and at the end you should do a massive water change to lower the nitrates. At that point, you can adjust your salinity as required.

But if i am getting a nitrate reading, doesnt that mean the right types of bacteria are present? I did not mean that the cycle was done.
Also, i took another salinity reading, it appears to have dropped again by about .0005 (totally a guess, it's just down ever so slightly every day on the hydrometer.

Day three
Ammonia: 1.0 or greater
Nitrite: >1
I've got the liquid test kit that changes color. As far as i can tell there has been no change in either. I figure i'll wait on the Nitrate tests until these two show signs of declination.

 

[Kurt_Nelson]

But if i am getting a nitrate reading, doesnt that mean the right types of bacteria are present?

Maybe... but you said you never took nitrate readings beforehand, so you don't know if your nitrate was really zero to start with. A jump from 0 to 20ppm nitrates in one day seems like an awful big jump. Not sure if you're using RO/DI water or tap water, but if using tap water your nitrates may have been that high to start with. You could test up some stored "fresh" saltwater if you have any, and probably get a feel for what your nitrates were to start with.

Regardless... I took your comment about having the right bacteria as an indication that you thought you were good to go.

You using a floating glass hydrometer, or a swing-arm? If swing arm, then as others have said, investing in a refractometer is a really good thing.

 

[Luke]

It's an instant oceean brand hydrometer. You poor water in the top and an arm floats up so far. So guess it's a swing arm. I'll for sure be investing in a refractometer before i get to the fish stage.

I am using distilled water and Instant Ocean Sea Salt. I suppose i just assumed that my nitrates would be zero. I did not know they could already have been present.

This leads me to another question. Does anyone know if wal-mart carries 5 gallon jugs of purified water? It would be easier for me to get one of those, than to get 5-1 gallon jugs of distilled water from Hy-Vee, since gallon jugs is all they had.

 

[thincat]

I guess you will just have to give Wal-Mart a call and ask them.

 

[Luke]

I was afraid of that
Wal mart is 20 miles. Hy-vee is 5 hah.
I could use my tap water. We're on a private well. But after seeing the tank with distilled water in it....it's so clear.....

 

[cabezon]

Your local grocery store may have a water filter out front that you can fill a 5 gallon jug for $1.50 or so. All of ours do.

When you mixed the water in your tank, there may have been a lot sitting on the bottom that did not get mixed in. Now you will always mix your salt in another bucket. do not use your well water. the clarity has nothing to do with it, the amount of algae you get from tap water does.