Tank Upgrade and Increased Alk Consumption?

[atp0726]

Less than a week ago I moved from a a 40 gallon breeder size tank to a tank twice the size. I move existing rock, added around 40lbs of reef saver dry rock and replaced reef sand with new. first 3 days alk remained stable with normal dosing schedule at aprox 7.8 (Hanna dkh) then dropped down to 7.4 after a few days. I increased the dosage by 1 ml/day and it only dropped to 7.3 the following day. I added another 1ml/day to try and keep it stable and possibly increase a bit.

Previously in the smaller tank i dosed aprox 24ml/day and have a number of encrusted frags to small acro colonies. I basically moved the rock island they were on to the new tank without having to disrupt them to much. So, in there minds...lol it was just a large water change. They were growing under 2 radion gen 3 xr30s and i bought a aquaticlife hybrid to add to the radions and have been running the bulbs for 2hrs a day.

Could they already have started growing to warrant the increased uptake or is the new dry rock and reef sand absorbing it somehow? I know when i set up the previous tank i tried to start sps probably to early and at one point i was dosing a very high amount of alk. In that tank i discovered later that the parts of the sand bed and around the rock basically turned into rock. I tried to keep this short but looking for direction as to whether or not i should keep going down my current path or if i should re-evaluate what is happening in my tank. Calcium is holding steady at 450 btw.

 

[Billldg]

It could be several things causing this. It could be just testing error or it could be the consumption by the new tank. Its not likely that your corals are increasing the usage as the move will actually cause them to use less due to stress. More rock and sand can mean more precipitation into the rock and sand. Within reason, don't chase parameters as this can cause you to precipitate greatly into the rock and sand.

I read everything except the last 2 sentences, lol, and you just confirmed that you are precipitating into the sand. I would check you Mag and make sure its at or above 1380.

 

[atp0726]

It could be several things causing this. It could be just testing error or it could be the consumption by the new tank. Its not likely that your corals are increasing the usage as the move will actually cause them to use less due to stress. More rock and sand can mean more precipitation into the rock and sand. Within reason, don't chase parameters as this can cause you to precipitate greatly into the rock and sand.

I read everything except the last 2 sentences, lol, and you just confirmed that you are precipitating into the sand. I would check you Mag and make sure its at or above 1380.

My previous tank I was probably precipitating into the sand and that is what i am worried about here. So, how low do i let it get before i intervene? I did start chasing numbers this week and already added 2ml to the daily dosing amount and since Sunday alk has gone from 7.8 to 7.2 (tonight).

 

[Billldg]

2 ml isn’t much. I would start my checking your mag, low mag will allow precipitation to happen, try to keep it around 1380. If you only dropped .6 dkh in 5 days then that isn’t that much. You could do a one time dose to raise it back to 7.8 dkh. I also had to deal with the same issue. I started my stopping dosing for a week and raising my mag to 1500 ppm, the high mag will cause the alk and cal ions to be coated with mag ions not allowing to precipitate. Then I I started dosing again at a third of the previous amount and slowly adjusted as needed. Turns out I was dosing 3 times as much as I needed.

 

[Billldg]

Watch this video and it will explain what I am talking about https://www.bulkreefsupply.com/video/view/week-29-calcium-alkalinity-science-behind-a-healthy-reef/

 

[atp0726]

Watch this video and it will explain what I am talking about https://www.bulkreefsupply.com/video/view/week-29-calcium-alkalinity-science-behind-a-healthy-reef/

Mag is at 1500+ as of tonight. i have been slowly bringing it up all week, mainly because i want to start tracking what the corals are using and decide if i want to start dosing it.
Good, idea on adjusting with a onetime dose. I will check tomorrow and bring it up with baking soda.
I will check out the video. Is the new sand and rock absorbing the alk or is it really precipitating. My calcium is a little higher than i typically like at 450 with a alk in the 7 range but I wouldnt expect it to start precipitating. I have a healthy PH at 8.1 to almost 8.3 by lights out, maybe I should bring it down by unhooking my skiimmer line to outside air?

 

[Billldg]

That’s actually something else I did, I lower my ph from 8.3 to 8.2 to help with possible precipitation. Chemistry is a tricky subject for sure, I wish I could give you a sure fire answer as what to do, but their are so many possible factors as to why precipitation occurs that I can’t.

Mag is usually something that doesn’t get used up much, until I got my trident I wasn’t testing mag but once a month.

I am going to say that you are more than likely precipitating, like I said, corals are stressed when they are moved and usually stop, temporarily, using alk and cal and trace elements.

 

[Randy Holmes-Farley]

New rock and sand can nucleate the precipitation of calcium carbonate, which shows up first in alk demand because the percentage change in calcium is too low to detect with most kits.

 

[atp0726]

That’s actually something else I did, I lower my ph from 8.3 to 8.2 to help with possible precipitation. Chemistry is a tricky subject for sure, I wish I could give you a sure fire answer as what to do, but their are so many possible factors as to why precipitation occurs that I can’t.

Mag is usually something that doesn’t get used up much, until I got my trident I wasn’t testing mag but once a month.

I am going to say that you are more than likely precipitating, like I said, corals are stressed when they are moved and usually stop, temporarily, using alk and cal and trace elements.

New rock and sand can nucleate the precipitation of calcium carbonate, which shows up first in alk demand because the percentage change in calcium is too low to detect with most kits.

thanks Randy! So, do I just keep adjusting the alk so it doesn’t get to low for the coral assuming the new sand and rock will get saturated at some point?

 

[Randy Holmes-Farley]

thanks Randy! So, do I just keep adjusting the alk so it doesn’t get to low for the coral assuming the new sand and rock will get saturated at some point?

If precipitation gets going too fast, it can become self supporting and becomes a problem. Lower alk, pH and calcium, higher organics, phosphate and magnesium reduce it.

 

[atp0726]

If precipitation gets going too fast, it can become self supporting and becomes a problem. Lower alk, pH and calcium, higher organics, phosphate and magnesium reduce it.

Ok, NO3 is around 10, I struggle with keeping P04 up and in the new tank its been hovering around .03, tonight was .02. My ph got up to 8.25 today, that's after unhooking my outdoor air intake skimmer line last night. Alk was down to 7.1, from 7.2 yesterday. Calcium was at 450 a few days ago. I turned off my doser to let it drop.

-Should I stop dosing sodium carbonate and switch to bi-carbonate?
-Raise the phosphate?
-Alk is lower than its ever been. I have mainly Acropora, how low can i comfortably go before i have issues?