How much of an alk swing is acceptable?

[glennr1978]

i just added another clam and 9 (I think) sps frags to my tank so I've been trying to determine how much ca, and alk my tank is using now. I've noticed that before I do my daily dosages (B-ionic 2 part) my alk is at about 2.7meq\L, then a couple hours or so later when I test again it's up to about 3.7meq\L. Then at night when the lights go off it's back down to 2.7meq\L. Is this okay / normal? All the while Ca seems to be staying between 400 to 420 ppm consistently.

 

Also, the ph in my tank is a bit low, although very stable. Every time I test it's at 8.0 regardless of time of day or wether or not I just dosed for alk. Should I be concerned about this or not? All my corals are doing very well. In fact a few that I pegged for goners are now showing good signs of making a comeback.

 

As always, thanks for the help. -Glenn

[Weetabix7]

Wow, that's quite an Alk swing.

I'll be tagging along on this one to see what kind of response you get.

 

On a totally different topic, were you one of the people wanting some blue polyp purple monti cap from me?

If so, I've got some small frags right now that are doing really well.

[Rehype]

Im interested to the answer to this as well glenn. I have a similar issue .My Ph swings from about 8.4 during the day to 7.8 or 7.9 at night(even though i run fuge lights 24/7). My calcium is consistently 420 and my Alk is quite stable throughout the day.Im wondering if this is ok. Sorry to hijack your thread im just curious.

[glennr1978]

Wow, that's quite an Alk swing.

I'll be tagging along on this one to see what kind of response you get.

 

On a totally different topic, were you one of the people wanting some blue polyp purple monti cap from me?

If so, I've got some small frags right now that are doing really well.

Yeah I do want one. Pm me with more info please!!!

[PurpleUP]

My dKH swings from 8-11 daily. However, my target is 9.5. Typically, I'll gradually add 40ml of SeaChem's alkalinity buffer throughout the day to maintain this level. Not sure if I'm doing the right thing though.

[glennr1978]

bump

[polyppetey]

taggged

[glennr1978]

back to the top. come on somebody's gotta have some info on this subject!!!

[Weetabix7]

back to the top. come on somebody's gotta have some info on this subject!!!

 

Ask Tinyreef.

And YGPM on the frags.

[Lynden]

In my opinion they can handle a fair bit of change. I admittedly have no real science to back this up but it would appear that some people's alkalinity swings quite widely with little to no ill effect. I do know that in tanks heavily stocked with corals the pH can fly across the board and back every day as photosynthesis shuts down at night, and the amount of acidic CO2 builds up. Whether that effects the alk I am not sure.

 

I would call changes in dissolved organics more harmful. Still, like the rest of our chemistry it would probably be best to aim for the correct level, but do take into account the fact that the pH will swing unless you have, for example, a fuge with 24 hour lighting (as a source of CO2 uptake).

 

I am sure someone will add to this as I still am not completely confident on it...

[glennr1978]

In my opinion they can handle a fair bit of change. I admittedly have no real science to back this up but it would appear that some people's alkalinity swings quite widely with little to no ill effect. I do know that in tanks heavily stocked with corals the pH can fly across the board and back every day as photosynthesis shuts down at night, and the amount of acidic CO2 builds up. Whether that effects the alk I am not sure.

 

I would call changes in dissolved organics more harmful. Still, like the rest of our chemistry it would probably be best to aim for the correct level, but do take into account the fact that the pH will swing unless you have, for example, a fuge with 24 hour lighting (as a source of CO2 uptake).

 

I am sure someone will add to this as I still am not completely confident on it...

I've noticed most people run fuge lights on an opposite cycle as the display (like I do) to compensate for ph swings. Would it be more beneficial to run the fuge light 24/7, and if so, why?

[Lynden]

Forgot about that, in my opinion both are fine, and the reverse schedule is probably better as it will cause the pH to rise less in the daytime.

[shaggydoo541]

Alk swings are dangerous. I only know this because I am a moron and have been dosing so much 2 part that all my SPS hate me. I have been battling the high demands of my SPS dominated tank. I bought small frags and now they are turning into large frags. I have no ca reactor and rely solely on my own dosing abilities.... hence the issue.

 

I have raised ca dramatically with little to no reaction from my corals on occasion. On the other hand I have been playing around with alk constantly for quite some time now and the crazy fluctuations have killed several corals and many more are looking sad. Well maybe it was other factors but I have had wild swings in my alk and my corals are reacting negatively to these swings.

[Lynden]

Actually I agree, a friend of mine got a dodgy batch of salt and it killed all his SPS, and caused his LPS to recede. H etested and it had to do with his alk being crazy.

 

I am going to suggest something here, that since alk directly relates to an organism's ability to adapt to pH swings (because of the ion charges that they need to exchange to equalize) that perhaps a massive swing in alk did not kill yours or my friend's animals, but rather made them vulnerable to slight pH swings? Or course the above is purely speculative, and of course it's only if I remember correctly. The original source somes from another fishkeeping forum, however, so I would imagine I wouldn't be allowed to link to it.

[psam]

How much of an alk swing is acceptable?

 

Very little... 3.5 meq/L down to 2.5, roughly 3 dkH, spells STN for sps.

 

Wouldn't worry about normal pH swings (mine runs 7.9 - 8.4 or so daily), but make sure kH stable if you want to keep acro.

 

For testing, I wouldn't check kH before / after dosing (sounds like you test 2 or 3 times / day?). I'd suggest testing at, say, 9pm one night, and don't dose anything. Then test at 9pm the next night. See how much your kH drops in 24 hours, and adjust daily dose accordingly. Use the reef chemistry calculator to help as a guide for amounts of whatever product you're using.

[coolwaters]

wats STN? Super-twisted nematic?

 

btw thanks psam fr that site very useful.

[shaggydoo541]

stn - slow tissue necrosis

 

rtn - rapid tissue necrosis

 

At least that is what those meant to me Both can easily happen if your alk is fluctuating rapidly

[PurpleUP]

How much of an alk swing is acceptable?

 

Very little... 3.5 meq/L down to 2.5, roughly 3 dkH, spells STN for sps.

 

Wouldn't worry about normal pH swings (mine runs 7.9 - 8.4 or so daily), but make sure kH stable if you want to keep acro.

 

For testing, I wouldn't check kH before / after dosing (sounds like you test 2 or 3 times / day?). I'd suggest testing at, say, 9pm one night, and don't dose anything. Then test at 9pm the next night. See how much your kH drops in 24 hours, and adjust daily dose accordingly. Use the reef chemistry calculator to help as a guide for amounts of whatever product you're using.

 

This thread has sparked my interest b/c I dose manually, and quite a bit of the dosing requires more alkalinity buffer than anything else. I figured a decent calc reactor would solve my problem. So I was researching calc reactors online and found this statement in another thread:

 

"In gross generalized/simplified terms, the easiest way to look at alkalinity is like a buffer. It helps to prevent swings in pH. Swings in pH are not good. A higher alkalinity allows a more stable pH for the tank. A lower alkalinity, allows pH to move more easily. Once alkalinity is exhausted, (very low), then the pH of the water can swing rapidly. For frame of reference, pH is measured on an exponential scale, with 8.0, being 10 times higher than 7.0. Ideal pH for reef tanks is between 8.1 - and 8.5 as per Delbeek and Sprung in "The Reef Aquarium Vol 3". Most people I know try and keep it between 8.1 - 8.4.

 

What is important to figure out is why is your alkalinity swinging like that...

What all do you have in the tank? In my tank, I have relatively small acro's and not too many of them, but I have two clams, one Crocea, and one Derasa....and the Derasa is a calcium/Alk devouring monster.."

[glennr1978]

What is important to figure out is why is your alkalinity swinging like that...

What all do you have in the tank? In my tank, I have relatively small acro's and not too many of them, but I have two clams, one Crocea, and one Derasa....and the Derasa is a calcium/Alk devouring monster.."

I have about the same as you when it comes to livestock.

 

I did a 20% wc day before yesterday, and I've noticed that the alk isn't fluctuating quite as much now. My dkh test kit is made by Hagen nutra fin and it explains the readings a bit differently than what I usually see here (9.5, 10, etc). The kit gives values in meq\L. It says that the ideal range for sw (not reef) tanks is 105 - 125 meq\L. My tank consistently reads in the 120 range, can anyone tell me what that equals in the more commonly seen values???

[psam]

I have about the same as you when it comes to livestock.

 

I did a 20% wc day before yesterday, and I've noticed that the alk isn't fluctuating quite as much now. My dkh test kit is made by Hagen nutra fin and it explains the readings a bit differently than what I usually see here (9.5, 10, etc). The kit gives values in meq\L. It says that the ideal range for sw (not reef) tanks is 105 - 125 meq\L. My tank consistently reads in the 120 range, can anyone tell me what that equals in the more commonly seen values???

 

105 - 125 is not in meq/L. Maybe ppm?

 

Edit - here's a nice link to convert - http://www.saltyzoo.com/SaltyCalcs/AlkConv.php

Or a chart with pre-filled values here - http://ozreef.org/library/tables/alkalinity_conversion.html

[glennr1978]

How much of an alk swing is acceptable?Very little... 3.5 meq/L down to 2.5, roughly 3 dkH, spells STN for sps. Wouldn't worry about normal pH swings (mine runs 7.9 - 8.4 or so daily), but make sure kH stable if you want to keep acro. For testing, I wouldn't check kH before / after dosing (sounds like you test 2 or 3 times / day?). I'd suggest testing at, say, 9pm one night, and don't dose anything. Then test at 9pm the next night. See how much your kH drops in 24 hours, and adjust daily dose accordingly. Use the reef chemistry calculator to help as a guide for amounts of whatever product you're using.

Either I'm not testing correctly or my test kits suck because dkh reading are usually pretty stable and apparently the alk swings are very drastic.I'm using the crappy red sea marine alk test kit. I really have to guess the numbers for the readings since it goes by a fading color scale.In the morning when I test it's a lighter shade of blue (guessed to be at 2.7) and then a few hours later after dosing it's a brighter blue (which is just a bit brighter blue than the highest reading of 3.6 on the scale), that's where I came up with the 3.7. Obviously I'm most likely guessing inaccurately so do you guys have any recommendations for another test kit?

105 - 125 is not in meq/L. Maybe ppm?Edit - here's a nice link to convert - http://www.saltyzoo.com/SaltyCalcs/AlkConv.phpOr a chart with pre-filled values here - http://ozreef.org/library/tables/alkalinity_conversion.html

yeah sorry, it's mg\L. my daughter is screaming next to me as I type, kinda distracting.

[JG]

tagging along; good thread.

[glennr1978]

105 - 125 is not in meq/L. Maybe ppm?

 

Edit - here's a nice link to convert - http://www.saltyzoo.com/SaltyCalcs/AlkConv.php

Or a chart with pre-filled values here - http://ozreef.org/library/tables/alkalinity_conversion.html

I'm an idiot. The test kit is for kh not dkh, I'm assuming there is a difference. And the values are represented in mg\L.

[oogie]

wats STN? Super-twisted nematic?

 

I love it.... I think I might use this one instead of all complicated slow tissue necrosis....

 

Can you come up with RTN?

[psam]

I'm using the crappy red sea marine alk test kit. I really have to guess the numbers for the readings since it goes by a fading color scale.

I would recommend to buy a new kit,,, stat. That Red Sea kH test is garbage. For less than $10 you can find an API (aquarium pharmaceuticals) which is as accurate as LaMotte, Elos, or SeaChem, and very easy to use. Each drop = 1 dKH, sharp color change, not really open to much interpretation. Get a new kit as soon as you can. If you see a couple degrees swing on API, then worry a bit. Until then, that Red Sea kit is junk, your water could be perfectly fine.

 

BTW - want to see what STN looks like? alkalinity swings while away for Christmas... notice the nice clean part of the rock... coral tissue was there at one point...