New saltwater tank - hydrometer giving vastly different readings...did I do something wrong?

[phuxtick]

Hello everyone,

I am not necessarily new to the saltwater hobby....but it has been roughly 12 years since I last had a saltwater tank. I used to have a BioCube 14 gallon and never once had issues with an Instant Ocean hydrometer and getting good readings from the tank. Fast-forward 12ish years and I now have a Fluval Evo 13.5 and the readings are just all over the place.

I can measure in the center and it's pegging out at the high end. Front left corner, reading almost perfect. Back right corner just above the live rock, reading way too low. It's been a long time, so maybe I'm forgetting a step somewhere....or this hydrometer is just a plastic piece of crap? I ordered a refractometer that should be here tomorrow, but in the meantime...anyone know what's going on? I'm just trying to get this one started with the cycling for a few weeks before I add the CUC and then eventually some damsels to make sure everything is good to go.

Some things worth noting -

• I do not have the heater in yet, but it's been ordered (so the water is "cold" - low 70s)
• I do not pre-mix water in a bucket (though I probably should have) as I never did before when I had my other tank that did fine for years.
• I added the salt directly to the tank with water in it, slowly, right in front of the nozzles so it pushes it around the tank in hopes of helping it dissolve better.
• I am using Fritz RPM
• Tank has been running for 2 days now
• Yes, I realize I have a bunch of air bubbles in my sand I need to go sort out lol

 

[shwareefer]

I would think your water was homogenous by now but maybe not?

Anyway, the biggest culprit for faulty readings with a plastic hydrometer is air bubbles sticking to the swing arm.

 

[Sebastiancrab]

Welcome to R2R! I started out with a hydrometer too and found out it is worthless. In the future, I highly recommend you mix your salt ahead of time when you get critters in your tank. On the damsels, I learned the hard way that you better put them in the tank last after all your other fish have been there for awhile. I tried adding a chromis at the end and it was a big mistake. The damsel had to go back to the LFS. Damsels are normally very territorial and will bully a fish to death.

 

[phuxtick]

I would think your water was homogenous by now but maybe not?

Anyway, the biggest culprit for faulty readings with a plastic hydrometer is air bubbles sticking to the swing arm.

Yeah I would've thought so too - I've never had a tank take this long to settle in with just the salinity

ugh....I can't wait for the refractometer to get here tomorrow.

 

[phuxtick]

Welcome to R2R! I started out with a hydrometer too and found out it is worthless. In the future, I highly recommend you mix your salt ahead of time when you get critters in your tank. On the damsels, I learned the hard way that you better put them in the tank last after all your other fish have been there for awhile. I tried adding a chromis at the end and it was a big mistake. The damsel had to go back to the LFS. Damsels are normally very territorial and will bully a fish to death.

Yeah, lesson learned....going to try the refractometer route tomorrow to see if I can dial things in, but if nothing by the weekend I'm going to drain it and hit the LFS to grab a few jugs of pre-mixed salt water. Well, really I'm just gonna use their water from here on out regardless of me dialing in what's in there now or not lol....should make life much easier.

About the damsels - whoa :O I've always been told to toss in the damsels first as a canary fish to make sure things live before adding in more expensive fish since they are so cheap in comparison. I had a few domino and zebra damsels in a tank 12ish years ago and they never bothered anyone (they got a 3 week head start in the tank), but they did become food for my blue ribbon eel sadly. Either way, good to know - I might need to revisit my initial stocking in that case...

 

[WVNed]

LOL

 

[mikereefing]

When you get your refractometer, I 100% recommend you mixing your calibration fluid based on Randy's recipe here in the forums. I had 3 different brands of calibration fluid that had largely varied results. Ever since making my own calibration fluid, everything has worked fine and I never have to recalibrate my refractometer.

 

[Sebastiancrab]

Ok, the old school method of cycling is to use fish which honestly, is cruel. Buy some Seachem Stability (it's very inexpensive starter bacteria) and put in a small pinch of fish flakes in your tank everyday and wait two weeks. Then test the water. Then go slow, start out with one or two clownfish and give your tank's bioload a chance to grow. The LFS's saltwater is not going to give you the green light to be cycled.

Consider getting an RODI unit. It will pay for itself.

Suggest you read Ron Reefman's articles here and check out Bulk Reef Supply's videos on Youtube.

 

[phuxtick]

Ok, the old school method of cycling is to use fish which honestly, is cruel. Buy some Seachem Stability (it's very inexpensive starter bacteria) and put in a small pinch of fish flakes in your tank everyday and wait two weeks. Then test the water. Then go slow, start out with one or two clownfish and give your tank's bioload a chance to grow. The LFS's saltwater is not going to give you the green light to be cycled.

Consider getting an RODI unit. It will pay for itself.

Suggest you read Ron Reefman's articles here and check out Bulk Reef Supply's videos on Youtube.

Thanks! Gonna have to look into the articles and videos.

 

[phuxtick]

When you get your refractometer, I 100% recommend you mixing your calibration fluid based on Randy's recipe here in the forums. I had 3 different brands of calibration fluid that had largely varied results. Ever since making my own calibration fluid, everything has worked fine and I never have to recalibrate my refractometer.

Good to know...I'll go dig for that recipe and print it so I have it for when my refractometer shows up.