Alkalinity won't stay up

[helipilot]

Hi Guys,
Over the last month my Alkalinity won't stay up (target 9.0 dKh) and drops even when I increase my dosing. If I add the amount shown on a calculator and test a few minutes later it rises as expected but will return to lower levels (8.3 dKh) in a day even if I up the dose. I have noticed that my reactor sponges are becoming clogged with white sludge as well as my pumps. The water also looks a little cloudy/ powdery. For reference I have a 53G system and am now dosing 120ml of BRS Soda Ash solution daily which I think is too much for a 53G with mainly LPS and soft coral (Ca dose is 90ml/ day). My other parameters all look ok (Ca 400, Mg 1400). I d also dose Ca but I have offset that in time with the Alk and the drip tubes are also about 3 inches apart. I'm dosing both into the sump section with the return pump. I tried a 20% water change 2 weeks ago but that hasn't changed anything. Any thoughts on what is going on/ what I need to do to reset back to where I was?
Mark

 

[lapin]

First thought would be a testing error. New test kit?

 

[rennjidk]

Tank pic?

 

[helipilot]

Good shout, I use an Apex Trident for my Alk/ Ca and calibrated it, no change. I bought a Hanna Alk checker and, if anything, it reads slightly lower than the Trident.

 

[rennjidk]

Good shout, I use an Apex Trident for my Alk/ Ca and calibrated it, no change. I bought a Hanna Alk checker and, if anything, it reads slightly lower than the Trident.

Any signs of precipitation? Hard sand bed? Build up on heaters?

 

[helipilot]

Tank pic?

 

[helipilot]

Any signs of precipitation? Hard sand bed? Build up on heaters?

Yes a little white deposit on the heater.

 

[KStatefan]

120 ml seems like a lot for 50gallons. How much should that raise alk?

 

[rennjidk]

You're dosing roughly 3dKH a day. That's not a ridiculous amount by any stretch of the imagination. Are you staggering the dosing time of your Alk, Ca, and Mg additions so they aren't all going in at once?

It's hard to see how much calcareous algae you have forming from the blue lights, but it can uptake 2 dKH a day on its own.

 

[helipilot]

You're dosing roughly 3dKH a day. That's not a ridiculous amount by any stretch of the imagination. Are you staggering the dosing time of your Alk, Ca, and Mg additions so they aren't all going in at once?

It's hard to see how much calcareous algae you have forming from the blue lights, but it can uptake 2 dKH a day on its own.

120 ml seems like a lot for 50gallons. How much should that raise alk?

Yep just over 3dKH a day. I do have quite a bit of Coraline algae growing. I am dosing over 24hr period (only Ca and Alk, I manually add Mg) but have staggered the start time to hopefully stop dosing at the same time. Maybe I should dose Alk by day and Ca by night do you think?

 

[Justdrew]

I'm at 120ml a day on a 40 breeder. Sodium Hydroxide mixed to Randy's #1 strength.

 

[rennjidk]

Yep just over 3dKH a day. I do have quite a bit of Coraline algae growing. I am dosing over 24hr period (only Ca and Alk, I manually add Mg) but have staggered the start time to hopefully stop dosing at the same time. Maybe I should dose Alk by day and Ca by night do you think?

I just meant that they aren't coming in contact with each other. My dosing lines are all on a manifold, clipped onto the tank, so my pump heads are set 10 mins apart. Just give enough time for the solutions to thoroughly mix into the tank and not contact each other in a concentrated amount.

 

[helipilot]

It does look like there are small white particles in the water, though the video does make it look worse.

 

[helipilot]

I just meant that they aren't coming in contact with each other. My dosing lines are all on a manifold, clipped onto the tank, so my pump heads are set 10 mins apart. Just give enough time for the solutions to thoroughly mix into the tank and not contact each other in a concentrated amount.

Mine is set to start the Alk at 00:01 and the Ca at 00:10 and then equal amounts over the 24hr period, I guess there could be times where they overlap or are close if the intervals are different.

 

[rennjidk]

Mine is set to start the Alk at 00:01 and the Ca at 00:10 and then equal amounts over the 24hr period, I guess there could be times where they overlap or are close if the intervals are different.

Just make sure all additions are staggered. It the dosing lines are next to each other and they're both dosing at the same time, you're essentially mixing them together before adding them. Retest for an accurate dKH consumption as well, and then adjust. Easy fix.

 

[helipilot]

Just make sure all additions are staggered. It the dosing lines are next to each other and they're both dosing at the same time, you're essentially mixing them together before adding them. Retest for an accurate dKH consumption as well, and then adjust. Easy fix.

I've initially set them to dose over a 12hr period each and I'll see if that changes anything, if it doesn't then I guess I can rule out over dosing and add more, though the build up on the filters and pumps has me thinking that I may have too much going in or, as you say, they are mixing together.