Reducing Alk.

So my alk is sitting at 4.5 and my calc. is sitting at 380. Quite simply, things have stopped growing since my alk. and mag ballooned a few months back.

I need to reduce my alk significantly (mag already is down). I have done 3 15% changes over the last few weeks. I have seen it come down slightly (5ish to 4.5ish), but not to where I want it to be (3.0). I am thinking about doing one massive water change (50%) to bring it down (hopefully) into the 3s.

Also, I have a 6 month hold Hamilton DE 250 watt bulb that is 6 months old. I have a light dusting of brown algae/diatoms. Is that a sign of a dying bulb?

 

Just curious, what salt are you using, and what does a fresh batch test out at? And what is your Mag at now?

 

Mag was 1380 when I test last week (was 1600+). I wasn't doing water changes during this balloon, so can't say. I've been using IO.

 

You mean 3.0 meq/l???

 

He tests in meq/L. When I needed to get my alk down I just let my tank sit for awhile. took like two weeks for things to drop down low enough to where I was able to dose things up to where I wanted them.

 

Yes.

 

Well, nothing is growing in my tank so alk. just sits steadily. Won't drop naturally.

 

What are you using to test Alk??
I would NOT do drastic changes in the tank.Changing the Alk. by 1.5 in one day is dangerous. 4.5 is not horrible(if that is indeed the correct reading) and things should start growing at that number.I would confirm your test results with another kit if possible.
Go slow let it grow..................

 

I have been going slow for 4 months with no rewards (browned out and no growth). At this point, I think I just need to get my numbers to where they need to be and let things stabilize. Small water changes aren't accomplishing anything for my alk. and neither is time.

I'm using RedSea to test. Numbers have been consistently at 4.5 (12.6 dKH) for 2 weeks. I've already made drastic changes to the tank (LED to halide, new salinity, new feeding, higher temp), so I think I just need to drop my alk. where it needs to be and let things be. I don't see any good in prolonging the stress another several weeks/months.

 

Maybe that is the problem.
Chasing numbers and changing things constanly is not the goal.Stability is.Time should be your friend not your enemy.