Changing Water Parameters

charged · Sep 1, 2015

Hello,
I'm hoping someone can shed some light on why my water parameters are changing. My alk dropped from 8.4 2 weeks ago to 8.0 last week to 7.6 this week. My CA shot up from 500 to 550 in 2 weeks and my MG went from 1400 to 1500 in 2 weeks. Nitrates dropped from 20ppm to .5 in the same time period. I haven't added anything during that time period except for a poly filter pad. My fish are all healthy but my corals haven't shown much growth in 3 months. 125G has been established for 8 years. Have no issues w/algae. My chaeto(Sump) also hasn't grown. I usually do a 20% water change every 2 weeks but haven't during this time period. I'm running Pacific Sun Triton LED's.

Randy Holmes-Farley · Sep 1, 2015

The magnesium change is testing error. It never changes that fast unless you dosed a lot or did some huge water changes. Same for calcium.

Alkalinity does typically drop over time in reef tanks and needs to be supplemented. Calcium also drops, but more slowly.

charged · Sep 1, 2015

I re tested ALK and CA twice. Results were the same. MG was only tested once. Just a thought but is it possible that Coral line Algae can leach Calcium back into the water? My rock and Back of tank is covered w/it.

Randy Holmes-Farley · Sep 1, 2015

Nope. It is testing error, no matter how many times you test it with the same kits. It may just mean the kits are not working right as you are using them. That is VERY common, unfortunately.

charged · Sep 1, 2015

I was afraid of that. Been using the same Red Sea Kit for 6 months. Do you have any thoughts on the water testing from Triton?

Randy Holmes-Farley · Sep 1, 2015

I think it can be interesting, and I expect the values for the high concentration things like calcium are reasonably accurate.

I discuss my Triton results here:

My Triton Testing Results: By Randy Holmes-Farley
https://www.reef2reef.com/blog/my-triton-testing-results-by-randy-holmes-farley/

charged · Sep 1, 2015

Great write up. Thank You for the link. I'll order my kit this week. I see you use GFO. Are you using it for more than Phosphate? I haven't used any because algae is not an issue.

Randy Holmes-Farley · Sep 1, 2015

You're welcome.

Phosphate is about all GFO does in most situations, although it will bind some organics and silicate.

TD13 · Sep 1, 2015

Clean your vials. Let them sit in distilled vinegar over night and give them a goooooood rinse in RO. My RS test kits were acting goofy too, or so I thought. After a thorough cleaning they do great. Also, make sure the syringe is completely empty before drawing up the reagent. With the plunger at 1 ml the reagent is usually visible about .82 to .84 ml.

charged · Sep 1, 2015

TD13 said:
Clean your vials. Let them sit in distilled vinegar over night and give them a goooooood rinse in RO. My RS test kits were acting goofy too, or so I thought. After a thorough cleaning they do great. Also, make sure the syringe is completely empty before drawing up the reagent. With the plunger at 1 ml the reagent is usually visible about .82 to .84 ml.

Thanks. I cleaned them out and retested. Everything much more in line.