OMG - Sometimes, efficient can be too efficient.
So I was home sick today lying on my couch looking at the tank and I notice my Toxic Green Tort colony is not happy. I move up closer and see it is STNing like there is no tomorrow. What happened here? Everything else looks fine but I can see all white body inside out. Hmm, now I am pi$$ed.
I start testing the water parameters. Nitrate, PO4 are 0. Ca is at 450. Alk is reading 6.8. WHAT??? 6.8? I test ALK and Ca twice a month at least. How can ALK be at 6.8? It was at 9.0 2 weeks ago. This is a Sailfert Kit I test with. I am in disbelief and run out to purchase another test kit. Wife is on my case "You are sick, you took a day off where are you going? "My corals are sick. I have to do something.." Oh Well.
I buy a new Sailfert test kit and test Alk again. Ha! it is indeed a 6.8/7. WTF happened here? I start to dig further. I dose using BRS pumps which are controlled by my
Apex. I check the dosing time and they have not changed in months. I test the pumps and they are dosing fine as well. Stumped not sure what happened I look at the outlet for Alk dosing in Apex. It says OFF if pH > 8.29. Hmm. I remember putting that in there 2 years ago just to avoid over dosing ALK. But my pH is always at 8.2 - 8.23. Curious I check the pH in last 7 days and I find out it is 8.3 - 8.33
How is that possible? Alk is at 7 and pH is at 8.3? Something is not right here. What can it be? What changed?
Skimmer and Lights. It cannot be the lights because I know since changing to T5 my corals have not adapted to them yet. So the corals are not happier for sure to use up more ALK. I know this because my Ca levels were at 500 2 weeks ago so corals were not using any Ca for the first 2 weeks after changing the lights. This is when ALK was at 9.0 where I normally keep it.
Well, it has to be the skimmer. The skimmer is performing so well that there is a increased amount of oxygen in the tank. It is also skimming a bit wet than my SRO 8000xp. This is raising the pH to over 8.3 and as a result at least for past 1 week Apex is not dosing any ALK.
Viola! I never thought changing the skimmer will cause ALK headaches.
I hope no other colony shows sighs of stress. I might loose the toxic green tort colony though :-/
Sunny