Alkalinity dropped and tank improved

[Lavey29]

Greetings, I use Red Sea Coral Pro salt for weekly 10 gallon water changes on my XL300 tank. I typically always see Alkalinity around 9 to 10 after the change and very little drop during the week. After this weeks water change my alkalinity was 8.3 and the next day it was 8.0. I have noticed that my 6 month old tank has really improved in all areas now and my corals and fish seem to be thriving right now. I even see coraline algae in the tank now.

So, has my tank finally started to stabilize? Are my corals doing better and using alk now more then before? Will weekly water changes suffice still or should I start dosing alk to keep it in the 8 range which is where the tank seems to throve? I only have soft and LPS corals right now and the tank is about 1/3 filled with coral and 5 fish. Everything finally seems to be going good and I don't want to mess it up but want to be sure if I need ti supplement that I do so. I am testing daily to see how much the alk drops in 24 hours. All other parameters seem to be in the good range also.

Appreciate any advice.

 

[codyadams1133]

what salinity do you maintain, coral pro salt is supposed to be around an 11.5 Kh at 1.026, if you're doing weekly changes I don't see any reason to supplement if everything is happy still. if you still see it dropping I would start supplementing just enough to maintain it at the happy place ( 8-9 kh from what I've gathered from your post) . Ie I wouldn't supplement unless you're trying to stop doing as many water changes or you notice your kh isn't getting back to usual with the water changes.

 

[Lavey29]

what salinity do you maintain, coral pro salt is supposed to be around an 11.5 Kh at 1.026, if you're doing weekly changes I don't see any reason to supplement if everything is happy still. if you still see it dropping I would start supplementing just enough to maintain it at the happy place ( 8-9 kh from what I've gathered from your post) . Ie I wouldn't supplement unless you're trying to stop doing as many water changes or you notice your kh isn't getting back to usual with the water changes.

Interesting point, my salinity was always 1.026 but I noticed after my last water change that it was 1.025 so maybe my batch was off slightly. Does salinity affect alk? Do you think the slightly lower salinity has caused a drop in my alk? I can easily raise it back to .26 if needed today.

 

[codyadams1133]

So your calcium, carbonates (Kh), and Magnesium are directly proportional to the salinity. IE if you raise your salinity (concentration of salt and other ions from your mix), your Cal, Kh, and Mg will also raise as all those ions are contained in the salt.

I would let your salinity raise naturally vs adding salt also, always do any adjustments super slow.

if you use an ato, just turn it off and test salinity until it matches, top off with the same salinity water and then you can return on your ato, if you don't use an ato, just don't add any RODI until your salinity is correct.

 

[czoolander]

So your calcium, carbonates (Kh), and Magnesium are directly proportional to the salinity. IE if you raise your salinity (concentration of salt and other ions from your mix), your Cal, Kh, and Mg will also raise as all those ions are contained in the salt.

I would let your salinity raise naturally vs adding salt also, always do any adjustments super slow.

if you use an ato, just turn it off and test salinity until it matches, top off with the same salinity water and then you can return on your ato, if you don't use an ato, just don't add any RODI until your salinity is correct.

This is good advice I never thought of doing it that way . I run ATO and I noticed my last salinity was around 1.023 . I want to be around 1.025 . So last week I did a 10 g water change with 1.028 water and got my overall salinity to 1.024 . But maybe this method you suggested might be better for raising the salinity

 

[codyadams1133]

I had my salinity lowered once and did it your way with no issues, I just have noticed most peoples guesses are off and it's easier to let nature do it sometimes, as well as safer.

 

[Lavey29]

So your calcium, carbonates (Kh), and Magnesium are directly proportional to the salinity. IE if you raise your salinity (concentration of salt and other ions from your mix), your Cal, Kh, and Mg will also raise as all those ions are contained in the salt.

I would let your salinity raise naturally vs adding salt also, always do any adjustments super slow.

if you use an ato, just turn it off and test salinity until it matches, top off with the same salinity water and then you can return on your ato, if you don't use an ato, just don't add any RODI until your salinity is correct.

ok, I think I understand your advice. My last water change on Wednesday of 10 gallons in a 65 gallon DT reduced my salinity from 1.026 to 1.025 and that is why my alk dropped to 8? My mag is at 1470 and cal is at 440 so I did not really see any drop in those areas from the slightly lower salinity.

Just wait till my next change on wednesday and make sure I get 1.026 in my fresh salt water for the tank? Then my alk should be back up where it normally reads?

 

[Lavey29]

Ok, so interestingly my calcium number is at 502 and it usually stays around 440. Not sure why it jumped after the last water change but doesn't higher calcium cause the alkalinity to drop? Maybe this is why I am getting a lower alkalinity reading now this week?

 

[codyadams1133]

Ok, so interestingly my calcium number is at 502 and it usually stays around 440. Not sure why it jumped after the last water change but doesn't higher calcium cause the alkalinity to drop? Maybe this is why I am getting a lower alkalinity reading now this week?

Your theoretical readings for Red Sea Coral Pro Salt should be 450/11.5/1350 at 34.0 ppt and 465/12/1390 at 35.0 ppt, but even in a bucket of salt you're gonna not be mixed 100%, you may have had a little extra calcium, to me I wouldn't worry about it and just continue with a normal water change schedule.

 

[Lavey29]

Your theoretical readings for Red Sea Coral Pro Salt should be 450/11.5/1350 at 34.0 ppt and 465/12/1390 at 35.0 ppt, but even in a bucket of salt you're gonna not be mixed 100%, you may have had a little extra calcium, to me I wouldn't worry about it and just continue with a normal water change schedule.

I mixed it at 1.026 for 10 gallon water change but tank shows 1.025. Alk bumped up to 8.8 which is ok. Everything seems OK but I think I'm getting to the point where dosing may be required to sustain parameters. I've got a decent amount of LPS in the tank now and this terrific vendor I bought from today gave me my first real SPS frag to try out. Not sure my tank is ready for SPS yet but guess a tester free frag can't hurt to try.

 

[Phistergosh]

I mixed it at 1.026 for 10 gallon water change but tank shows 1.025. Alk bumped up to 8.8 which is ok. Everything seems OK but I think I'm getting to the point where dosing may be required to sustain parameters. I've got a decent amount of LPS in the tank now and this terrific vendor I bought from today gave me my first real SPS frag to try out. Not sure my tank is ready for SPS yet but guess a tester free frag can't hurt to try.

Something else could be going on like an issue with your refractometer.

If your overall salinity dropped from 1.026 to 1.025 with a 10 gallon water change, your new water had to be significantly less than 1.025. It would need to be around 1.17. so something is going on. Did you test the new water before adding to the tank? You always need to test it before adding.

 

[Lavey29]

Something else could be going on like an issue with your refractometer.

If your overall salinity dropped from 1.026 to 1.025 with a 10 gallon water change, your new water had to be significantly less than 1.025. It would need to be around 1.17. so something is going on. Did you test the new water before adding to the tank? You always need to test it before adding.

I mix my own rodi salt water with coral pro salt. Use a digital Milwaukee instrument refractometer and my mix was 1.026. My last tank reading was 1.025 not sure why it dropped maybe to much skimmer cup water but I thought my water change would bring it back up but still at 1.025. I can add a cup a day to the sump to nudge it up.

 

[Timfish]

Greetings,. . . Appreciate any advice.

I'd say the title of your thread should be "Tank improved and alkalinity dropped". Sounds like your system is maturing just fine. Numbers are always going to be changing and I'd suggest for th first year checking pH, alkalinity, calcium and magnesium weekly so you get a good feel how your animals are messing with them.

 

[Lavey29]

I'd say the title of your thread should be "Tank improved and alkalinity dropped". Sounds like your system is maturing just fine. Numbers are always going to be changing and I'd suggest for th first year checking pH, alkalinity, calcium and magnesium weekly so you get a good feel how your animals are messing with them.

Yes, as I learn more about this hobby, your version is more accurate. Since I've been able to keep more stable parameters, the corals are growing and using alk albeit small amounts due to only LPS and softs in the tank. Water changes seem to replenish everything ok but I can foresee the not so distant future needing to dose alk and cal probably especially if I try a few SPS at some point.