A way to lower alkalinity safely?

[mattz]

Hi,

My alkalinity is extraordinarily high and I'm looking for a safe way to lower it, aside from the obvious - water changes. pH is showing as ~8.4 and I tried my Alk test kit on someone else's water (it appears it's not a test kit flaw). I'm not looking to take a shortcut here, but I'm trying to avoid spending an insane amount of money on new salt and RODI water. Anyone have any thoughts or ideas? Are there any commercial products out there for this purpose that anyone knows of?

Thanks in advance.

mattz

 

[NateHanson]

What's your alkalinity reading?

 

[BOSTONBAKEDBEAN]

ive been told add calcium.

 

[NateHanson]

Adding calcium could cause a crash precipitation of CaCO3, and while that would certainly lower your alkalinity, it would do it way too fast. I'd think your high alkalinity isn't as much a problem as the possibility of it dropping really fast. That would probably kill a lot of corals.

It depends how high you're talking about. If it's 15 dKH, then just let it come down by itself over a couple weeks. If it's 20 dKH, then I'd start doing small water changes (maybe 15%) once each day, until it's down where you want it.

I think the key here is slow changes. I've heard of many tank crashes blamed on rapid alkalinity changes.

 

[mattz]

sorry for not responding sooner, but thanks to everyone for their help. Nothing's living in the tank at the time (not fish or inverts), so I can afford to make some large(r) water changes without disrupting the system too much. My alk reading was waaaaay high - in my salifert kit, it was taking 4 syinges of the reagent to trigger the color change. I think the source (not confirmed) was that one of my kids decided to "help" by putting in baking soda. I've done a total of about 60% water changes in the past few weeks and that's helped.

 

[RayD]

I don't think 8.4 is too high a pH depending on the time of day.

 

[MichaelJ]

My alk reading was 18 now it's 14, I did a 5 gallon change 2 days ago and then did a 15% water change today..... and 14 is the current reading. So the small water changes that were suggested definately helped me.