total alkalinity high...?

[Linckia laevigata]

We have a 1500 gallon system.
Illuminated by 21 250w 14k metal halide lamps.
Our systems calcium is supplied by a large reactor controlled by a German made pH controller.
Salinity 1.23 -- Red Sea Mix
pH 8.0
calcium 450
dKh 9.1

Our system ran for 3 months without failure, suddenly pH dropped to 8.0 and water became murky, quick assumption alkalinity to high.

Truth be told...

Saying this what could have suddenly changed the parameters within the system.

Is it remotely possible that oxygen levels within the area depleted thus lowering pH?

How do we explain high total alkalinity?

We were using heavy pvc glue within the related area, perhaps the glue had some adverse effect.

Someone with any valid information, please do reply.

Moreover, what to do to rectify?

[Randy Holmes-Farley]

I don't see a high alkalinity. I usually recommend 7-11 dKH for reef aquarium alkalinity.

Cloudiness can be a bacterial bloom, spawning of soemthing in the aquarium, precipitation of CaCO3, or possibly other things.

Is it still cloudy?

[Linckia laevigata]

Hi Randy,

Assuming natural seawater being 7.3 dKh, that 9.1 was considered high.
Cloudiness still apparent (murky white), cleared up a little, pH hovering around 7.90 within the reactor, 8.05 within the system, calcium 450
Perhaps you can tell me why calcium carbonate would suddenly precipitate? Is it possible that the pH controller is set to high?
And if how do we explain the sudden drop in pH within the system 8.0, it had been consistent 8.30 for weeks.
Thanks for your response.
--Cynthia

[Randy Holmes-Farley]

I think you will find that most aquarists on Reef Central would not consider 9 dKH high. Many keep alkalinity above that, and it is not high enough to induce a precipitation event unless the pH is very high (well above 8.5).

Unless you spiked the pH up, or added a lot of a buffer or alkalinity supplement, I do not believe that you have a precipitation event.

A bacterial bloom can also reduce pH as the bacteria produce CO2.

[Linckia laevigata]

It is very well possible that a bloom is in effect.

That same day we had the overhead lighting (poor spectrum 5500k) on for 15 hours, in addition to which, the system was illuminated under 6000w 10/14k for 8 hours, perhaps to much lighting caused the related bloom.

Perhaps a reduction in light will hinder this bloom, what do you think?

[Randy Holmes-Farley]

Bacterial blooms are usually caused by adding something organic to the water. Did you add anything like a new food, or spill something into the tank?

Usually they go away on their own.

[Linckia laevigata]

Only recent additive was Kent's phytoplex (phytoplankton) on June 10th, what was not consumed was picked up by the skimmer.
Perhaps air pollute, could it be that the pvc glue within the room caused some sort of negative reaction.
Who knows, very unusual and a rather sudden change, perhaps one of the parties helping install a new fish system accidentally dropped something in the tank. No unusual smell from the water. Time will tell, hopping it is only a bloom. Corals look o.k. thus far.
Thank you again for your help.

[Randy Holmes-Farley]

You're welcome.

If it is a bacterial bloom make sure to keep the aeration up as O2 can be consumed by bacteria.

[Linckia laevigata]

Please to say water clarity is back to normal, pH level is normal.

[Randy Holmes-Farley]

:thumbsup:

Let's just hope it doesn't happen again. :)