Alk

[turtleone]

I Just upgraded to A 75 gallon tank, from A 25 gallon. I had to do this rather quick do to the fact that 25 cracked. So I will give a quick update. I added all new live sand to the 75gallon Carib Sea.( Did not transfer any of old Substrate over) I only have about 50 ILBs of live rock in the 75. Bye the way I added 80 ILbs of the Carib Sea live sand. For flow I have added two Korella 1080, they are placed at upper corners of tank. so I can get some surface breakage. I also have Reef octopus BH 1000 HOB skimmer. I recently added A penguin bio wheel to remove remaining debris, also so I can run carbon. Now after the update to get to my question. I can not keep My Alk level up. It stays around 7 DKH using API test kit. I am supplementing with the Bulk Reef supply Soda Ash also dosing the calcium solution as well I test its At seven It takes about 100 ml to bring to eight, I do this around 4:00 pm then at about 10:30 I will add another 100ml but also dose about 100ml of calcium additive with it. Mag was low and now at 1350 and holding calcium also at 450ppm. Calcium has remained at 450 through all this. Take that back was at about 500ppm but for two days just dosed alk. then came to 450 and sine dosing equally at 10:30 remained at 450ppm Alk is only issue. Sorry for being so long just trying to give as mutch info as possable. All corals along with fish Are doing OK. Corals are not perfect but think there adapting to new light went from A 4x24 T5 to the marine land pro with 4x54watt T5 and duel 150 HQI

[ek9vboi]

Only a few things I can assume.

1. Majority of the saltwater is new, BUT not mixed by yourself.
2. You have not checked your Magnesium level

I was going to say that your mag levels might be low and therefore the alk is precipitating as soon as it hits the water. BUT even so, with a majority of new saltwater the mag level shouldn't be that low.

My recommendations are to check your mag level and if your not mixing your own saltwater then start. Not pointing fingers but if you bought saltwater from a LFS, do testing before adding it to your tank so you can get a general parameter.

Only other way to fix this for the best are water changes. Maybe 25% or so water changes and continue that routine for a few weeks till overtime the old water gets replaced. That or use baking soda to bring up the alk and continue with the 2 part dosing if needed.

[turtleone]

mag level is at 1350 as i stated above. I did mix mostly all new saltwater using RO water i did however use Oceanic salt mix witch was all I could find in my area. I did however use about 15 gallons of old water I originally had placed corals and fish in Rubbermaid container for a few days till I could get tank set up and tmp stable.

[bertoni]

If I understand correctly, you're dosing about 2 dKH per day into the tank. You might just need to dose more. A fair number of tanks consumed 2-3 dKH per day. Are there any signs of precipitation? The soda ash is higher in pH and might tend to cause more precipitation than the baking soda version, but both usually are fine.