Is alk 6.4 dhk to low for sps?

[adam finley]

Like the title says is the alk level too low for sps. I have some stylo’s that are doing good but most of the other sps kinda don’t do much of anything and a couple have slowly perished. Since I’ve been checking with “Hanna” it’s remaind pretty much betweeen 6.3-6.8. I have a 40b with 20 sump and do 5-10 gallon water change biweekly.

 

[Geebs19]

Its pretty low. What kind of salt are you using? Dosing?

 

[Nburg's Reef]

It's too low for SPS or any coral really, SPS might be more affected than others tho. You can easily raise alk with water changes and maintain it with periodic testing and dosing.

If you have SPS in there and coraline growth, it will use up calcium and cause alk to drop. probably more so than what your water changes are doing. I had an SPS dominate tank and I ran out of 2-part and my alk dropped close to 1 unit overnight.

 

[adam finley]

Its pretty low. What kind of salt are you using? Dosing?

Not dosing yet but instant ocean reef crystals.

 

[FGourdin]

Too low. Use a higher all salt. Better off with the All in the 7-8 range.

 

[Nburg's Reef]

If you're going to take on SPS, I would suggest testing alk every night at the same time and invest in some 2 part. You can get several months worth for cheap with Bulkreefsupply.com if you don't mind manually dosing every day... like feeding your fish. But I would also suggest a doser. I have been using the BRS dosers for a long time as they are inexpensive and hold calibration pretty decently. I don't know what your reefing budget it, but for 240 bucks you can really keep your alk stable and you will notice your SPS and other hard corals take off! SPS will be impossible if your alk is not stable.

 

[adam finley]

If you're going to take on SPS, I would suggest testing alk every night at the same time and invest in some 2 part. You can get several months worth for cheap with Bulkreefsupply.com if you don't mind manually dosing every day... like feeding your fish. But I would also suggest a doser. I have been using the BRS dosers for a long time as they are inexpensive and hold calibration pretty decently. I don't know what your reefing budget it, but for 240 bucks you can really keep your alk stable and you will notice your SPS and other hard corals take off! SPS will be impossible if your alk is not stable.

I have been testing once a week recently and I was kinda leaning towards dosing. Everything in my tank does good except for a couple sps I have. My Stylo’s are growing pretty good and a few other similar sps are doing good overall. But I have a digi and red planet I just got that aren’t dying but not thriving either. Also I had a few other previous sps that perished when I was testing the waters.

 

[spsick]

If your tank is accustomed to running that low, no. I run around 7 and have dipped that low occasionally with no issue. If you run at 9 maybe not so much.

Also if you are using RC and doing regular water changes and your tank isn’t packed with hard corals, I would strongly suggest picking up like a Salifert test kit to verify your results. That seems awfully low for using one of the highest Alk salts available.

 

[Nburg's Reef]

In my experiences, some acroporas can take months to "wake up" after you get them. Also in my experiences, stylos are more suseptable to slow death with unstable alk and low nutients where acros will just kinda go dormant. In past tanks, Stylos and birds nests grow fast but can also die fast. Weird that I always have bad luck with easy sps but do just fine with more demanding.

Anyways, as those sps grow, the demand for Calcium will go up and up and your alk swings will only get worse. Dosing is easy once you dial in your daily dosage.

 

[adam finley]

If your tank is accustomed to running that low, no. I run around 7 and have dipped that low occasionally with no issue. If you run at 9 maybe not so much.

Also if you are using RC and doing regular water changes and your tank isn’t packed with hard corals, I would strongly suggest picking up like a Salifert test kit to verify your results. That seems awfully low for using one of the highest Alk salts available.

I’m using the Hanna checker for Alk. I do have quite a few lps and softies in the tank could they be using up the Alk?

 

[Nburg's Reef]

Softies and LPS will use some but not a lot. My 40g sps tank used around 25-30 ml of 2 part per day, my 116g softie/lps witha few acro frags uses <10 ml per day.

Coraline and sps uses a LOT. Anything that grows thick skelletons quickly will use a lot.

 

[adam finley]

Softies and LPS will use some but not a lot. My 40g sps tank used around 25-30 ml of 2 part per day, my 116g softie/lps witha few acro frags uses <10 ml per day.

Coraline and sps uses a LOT. Anything that grows thick skelletons quickly will use a lot.

Well I just purchased some 2 part from BRS and will manually dose to get it too around 7.5 and see if that helps any. So to test how much my system uses and needs do I just test a couple consecutive days and calculate the difference in Alk?

 

[Nburg's Reef]

Well I just purchased some 2 part from BRS and will manually dose to get it too around 7.5 and see if that helps any. So to test how much my system uses and needs do I just test a couple consecutive days and calculate the difference in Alk?

Have you tested your calcium as well? If your alk and calcium are low, which they probably are, you can dose 2 part or do some larger water changes to get to 7.5, or even better 8.5 -9. If Calcium is high and alk is low, then there is something funky going on and definitely water changes and make sure you have good rock/sand that buffers the water. Reef crystals has high kH, so you can probably do a 10g water change and raise your kH to a good level, then start dosing.

Once you get to a desired kH, dose a smaller amount, like 5-10ml per day and test every day at the same time or every other day for a few weeks to see your tank's demand. Alk can change rapidly so I recommend several time per week until it stabilizes. Once you get stable kH, your SPS may start to grow from the stable environment and then increase demand from being happy and healthy, and you'll need to increase your dosage, so your dosage will go up and up.

Once you start dosing, you can also use your alk as a way of determining coral growth. If you have been dosing X amount and kH is steady, then all of the sudden your kH goes up, that means your coral may have stopped growing and stopped using up kH... something is wrong! Or the opposite, if kH starts shifting down, you coral growth rate may be going up.

I would try to raise the alk to somewhere less than 1 kH unit per day. Big swings are never recommended, best advice in this hobby, nothing good happens fast. Maybe shoot for 7.5 initially then creep up to 8.5. 7.5 is closer to the ocean kH, but not always recommended in smaller reef tanks because you have little room for error. At 8.5-9, you have a little buffer room before alk drops to dangerous levels. Some reefers even go as high as 12 kH and have great success, but I wouldn't recommend it because that requires juggling other things like light intensity and water nutrition.

This may seem confusing or overwhelming, but once you dial it in, everything else in reefing become much, much easier! You will learn that all successful stony tanks may only share a few things in common, but one will always be stable kH.

 

[adam finley]

Have you tested your calcium as well? If your alk and calcium are low, which they probably are, you can dose 2 part or do some larger water changes to get to 7.5, or even better 8.5 -9. If Calcium is high and alk is low, then there is something funky going on and definitely water changes and make sure you have good rock/sand that buffers the water. Reef crystals has high kH, so you can probably do a 10g water change and raise your kH to a good level, then start dosing.

Once you get to a desired kH, dose a smaller amount, like 5-10ml per day and test every day at the same time or every other day for a few weeks to see your tank's demand. Alk can change rapidly so I recommend several time per week until it stabilizes. Once you get stable kH, your SPS may start to grow from the stable environment and then increase demand from being happy and healthy, and you'll need to increase your dosage, so your dosage will go up and up.

Once you start dosing, you can also use your alk as a way of determining coral growth. If you have been dosing X amount and kH is steady, then all of the sudden your kH goes up, that means your coral may have stopped growing and stopped using up kH... something is wrong! Or the opposite, if kH starts shifting down, you coral growth rate may be going up.

I would try to raise the alk to somewhere less than 1 kH unit per day. Big swings are never recommended, best advice in this hobby, nothing good happens fast. Maybe shoot for 7.5 initially then creep up to 8.5. 7.5 is closer to the ocean kH, but not always recommended in smaller reef tanks because you have little room for error. At 8.5-9, you have a little buffer room before alk drops to dangerous levels. Some reefers even go as high as 12 kH and have great success, but I wouldn't recommend it because that requires juggling other things like light intensity and water nutrition.

This may seem confusing or overwhelming, but once you dial it in, everything else in reefing become much, much easier! You will learn that all successful stony tanks may only share a few things in common, but one will always be stable kH.

Thanks for all the help. I just ordered the BRS 2 part and sailfert calcium test kit. Part of the issue could be I need to do bigger water changes. But usually if I do that my nitrates get really low next to 5 or less and I try to keep that around 10. So hopefully I can get things on track with a little dosing. Before I start should I do a water change and test the Alk and calcium to see where it’s at? I noticed also my salinity was slightly lower .023 when usually I keep it at .025. My refractometer was a little out of adjustment.

 

[Nburg's Reef]

I would do a 5g water change, that should get you back in the 7 range, then a day later, do another 5g change. Also, get your salinity to 1.026 or 35ppt. Low salinity will reduce your alk capacity.

The two water changes should get you close. Then start your dosing regiment. I personally use instant ocean because it has lower alk so less alk swing on water changes but instant ocean is fine as long as you avoid huge water changes. Its dKH is 13, so a big water change can make a big alk swing.

Hope this helps and good luck!

 

[fnlyreefready]

Softies and LPS will use some but not a lot. My 40g sps tank used around 25-30 ml of 2 part per day, my 116g softie/lps witha few acro frags uses <10 ml per day.

Coraline and sps uses a LOT. Anything that grows thick skelletons quickly will use a lot.

I think I’m currently dosing 4 ml of alk a day Went from 10. - 8.8 in a week. Mostly have euyphillia I’m gonna test alk at 2pm during light cycle for the next 3 days and see if I am raising or lowering still haven’t seen any dramatic swings using a coral vue to dose After skimmer have about 50 heads of frogspawn/torches/hammers/octos. With some hard corals. I think I counted 30 total corals in today (125, 30 gallon sump. Skims digital view skimmer with no fuge.) what I’ve really been having issues with is I have 0 nitrates because my corals use it as fast as my 9 fish can produce it even with over feeding it seems to make 0 difference.

 

[Bacon505]

You want to look for stability instead of chasing numbers. My 160g system run on 6.4 alk and 380 cal.

 

[Henryb9]

I run mine around 6.3 to 6.8 and have a mixed tank. So I don’t think there should be an issue.

 

[KarlsReef]

Being from the UK I se comments regarding Instant Ocean Reef Crystals, mostly seem to lead to issues in tank stability. I'm glad that we don't seem to have this salt very widely over here, as to me it would appear this "cheap beginner" salt would be the cause to many problems and tbh I don't know why it's still being produced or purchased... Well I guess it's a cycle of its being produce because people are buying it, I don't get why a shop worth its salt (excuse the pun) would recommend it. I know there are people that swear by it but most expert reefers may have started with it have found alternative salts and move away and when they do have higher success. While I'm not saying it's the reef crystals causing the low Alk, I'd say get something different, slowly switch over by doing smaller changes and gradually increase the amount of new water until you reach your desired or normal water change amount.

 

[reefinatl]

Being from the UK I se comments regarding Instant Ocean Reef Crystals, mostly seem to lead to issues in tank stability. I'm glad that we don't seem to have this salt very widely over here, as to me it would appear this "cheap beginner" salt would be the cause to many problems and tbh I don't know why it's still being produced or purchased... Well I guess it's a cycle of its being produce because people are buying it, I don't get why a shop worth its salt (excuse the pun) would recommend it. I know there are people that swear by it but most expert reefers may have started with it have found alternative salts and move away and when they do have higher success. While I'm not saying it's the reef crystals causing the low Alk, I'd say get something different, slowly switch over by doing smaller changes and gradually increase the amount of new water until you reach your desired or normal water change amount.

Not sure why a 2 year old thread got bumped but RC has very high alkalinity. Generally there are two reasons people avoid it, some amount of residue when mixing makes some uneasy and the high alkalinity.