Low pH and Alkalinity on new cycling tank

[EchoPear]

Greetings everyone. Have a tank cycling with an uncooked shrimp right now, has been going for about 48hrs now. HOB filter, CaribSea Liferock, caribsea ocean direct, saltwater mixed to 35ppt with reef crystals and store bought distilled water

I have been testing with some Aquarium Co-Op test strips I have from my freshwater tanks. I was under the impression that strips like these could be used for either fresh or salt. The problem is that even after 2 days of aeration in the tank, my pH is in the low 7s (moderate area in pic) and my KH is firmly in the lime green low 40ppm which according to conversion table is a Alk of like 2.5 dkH. What is going on? Jeff from Saltwater radio podcast had said the two are linked, I’m thinking either my refractometer is not accurate or my test strips are useless in saltwater. The refractometer is just a generic one I bought from chewy, the instructions had me calibrate it to zero with just RO water - I used distilled water the same I mixed my saltwater with. Any thoughts on what is happening?

 

[Randy Holmes-Farley]

IMO, you need better measuring devices. Try them in some new salt water.

Both alk and pH decline during cycling, but not to the levels you note unless you added large amounts of ammonia many times.

 

[Randy Holmes-Farley]

FWIW, I’ve never understood how a test strip could even hope to measure the alk of seawater since it is comprised of multiple different things.

 

[EchoPear]

IMO, you need better measuring devices. Try them in some new salt water.

Both alk and pH decline during cycling, but not to the levels you note unless you added large amounts of ammonia many times.

Wanted to update. I ended up getting an API kit, and pH is more normal, 8-8.3. I also grabbed some refractometer calibration fluid, and the 35ppt solution was reading 36-37ppt. So thanks for the advice!

 

[SuperReefNoob]

Wanted to update. I ended up getting an API kit, and pH is more normal, 8-8.3. I also grabbed some refractometer calibration fluid, and the 35ppt solution was reading 36-37ppt. So thanks for the advice!

The API kit is a great start but just know they have a history of spotty results...i started with an API kit but eventually threw the whole mess away as it consistently read zero nitrate, took a water sample to my LFS and my nitrate was over 100....immediately upgraded to all Hanna equipment...

 

[EchoPear]

The API kit is a great start but just know they have a history of spotty results...i started with an API kit but eventually threw the whole mess away as it consistently read zero nitrate, took a water sample to my LFS and my nitrate was over 100....immediately upgraded to all Hanna equipment...

Already broke one of those flimsy test tubes… stabbed myself lol. Those Hannas are already on my wishlist!

Might have stalled my cycle. I did a 100% water change and added a yellow clown goby since I was producing nitrates. I did also add another Carib sea life rock to the top of my pile so maybe that is what stalled it. That or I am having the same issue you did, with false 0 readings. Trying to shake everything slightly longer than it says for insurance. Been dosing prime/stability in meantime as still reading nitrites.