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View Full Version : how many sps dominated target alk around 7.5??


sensei
08/28/2017, 11:29 AM
I have read that many encounder issues when alk is above 8.0???
thank you for your comments

Potatohead
08/28/2017, 11:43 AM
I won't say I have had issues over 8, but the highest my tank has been is only 8.2. I run it around 7.3 - 7.4 typically and corals seem happy there.

There seems to be a correlation between alkalinity level, nutrient level and lighting level. None of it is really proven but typically really high light does better with higher nutrients and higher alkalinity. Lower nutrients seems to do better with lower alkalinity and (slightly) lower light.

Wazzel
08/28/2017, 11:55 AM
I run mine between 7.5 and 8.0.

Bpb
08/28/2017, 11:57 AM
I target 7-7.5 usually but don't sweat it if it gets a little outside that


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DivingTheWorld
08/28/2017, 12:35 PM
I target 7.5. I find that when I get around 8, my acros are fine but my Monti Caps start to go south. They recover just fine if I drop back down though.

Usernam Invalid
08/28/2017, 02:00 PM
My system is happiest at 7.8

jda
08/28/2017, 03:28 PM
I don't have issues above 7.5 unless I try and chase my N and P down to nothing with organic carbon. 8.0 or 9.0 will get me the same results. I just like to keep it around there because that is most close where NSW is at and I do not believe that these organisms spent millennia figuring out how to thrive in their natural environment only to have us tweak with it.

Keep in mind that before ULNS, zeo and the other pay-to-play "systems" people had sweet SPS tanks with 12.0 alk and 450 calcium.

murphreef
08/28/2017, 03:36 PM
Ive always kept mine from 7.8 - 9 with no noticeable issues.

WLachnit
08/28/2017, 03:43 PM
I've always wondered this as well. I have been in the high 8s but have now lowered to 8. Haven't really noticed a difference.


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vhuang168
08/28/2017, 03:54 PM
9.5-9.8. No issues if I keep nutrients about 2-3 ppm NO3 n 0.003 ppm PO4. If nutrients drop below that, I start getting pale colors n bleaching. If too long I start to get tip burn.


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notenoughtanks
08/28/2017, 04:02 PM
I'm usually 7.1

DiscusHeckel
08/28/2017, 04:25 PM
My corals seem happy below 7 dKH. For this reason, I try to keep alkalinity between 6.55-6.8 dKH.

Potatohead
08/28/2017, 05:03 PM
My corals seem happy below 7 dKH. For this reason, I try to keep alkalinity between 6.55-6.8 dKH.

One of the best sps guys in town here with a big frag system keeps his really low as well. I tested one time from some bag water out of curiosity and got 6.1.

JustinM
08/28/2017, 05:15 PM
I keep mine around 7.5 to 8. If it goes below 7.5 my spathulata polyps go in.

sensei
08/28/2017, 09:21 PM
My corals seem happy below 7 dKH. For this reason, I try to keep alkalinity between 6.55-6.8 dKH.

I thought that going bellow 7 would be a problem for acros?
what is the lowest you have ever had it?
have you noticed problem at that level?

Thanks a lot

Bpb
08/28/2017, 10:02 PM
I thought that going bellow 7 would be a problem for acros?

what is the lowest you have ever had it?

have you noticed problem at that level?



Thanks a lot



Alkalinity has a general trend along with inorganic waste levels. The higher you keep those nitrogenous and phosphate type wastes, the higher you can run alkalinkty. The cleaner the water gets, the more sensitive it becomes to alkalinity and you really are best off keeping it lower. I've run mine as low as 6.0 for years and had tremendous growth and zero problems. Unfortunately it's bouncing around between 7-9 right now while the calcium reactor is offline and I'm tying to dial in kalkwasser till I get the reactor fixed. Due to that I'm feeding more as to not trigger a tip burn scenario.


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murphreef
08/29/2017, 02:01 PM
Tank got a bit over 9 and yup started noticing some burnt edges along my caps and a few sps. Gotta get it back down towards 8.

Never really realized how low nutrients means you gotta keep your tanks alk close to 8 as possible.

DiscusHeckel
08/29/2017, 03:01 PM
I thought that going bellow 7 would be a problem for acros?
what is the lowest you have ever had it?
have you noticed problem at that level?

Thanks a lot

When alkalinity drops below 7 dKH, its pH buffering capacity drops significantly. This is something to bear in mind. In my case, I dose limewater over a period of 14 hours in a day. So, low pH is not an issue for me.

Alkalinity in my tank can occasionally go down as low as 6 dKH either due to dosing problems or increase in growth or precipitation. On three occasions, however, it went down as low as 5.4 dKH due to a limewater dosing issue. When this happened, I raised alkalinity back to normal range over a period of two weeks. Nothing happened to any of my Acroporids. In fact, my corals did not exhibit any external stress signs when alkalinity sank this low. I discovered it by accident while checking my plugs. I simply forgot to switch on the power of my kalk stirrer after replenishing calcium hydroxide.

If inverse had happened, i.e. alkalinity spiked upwards suddenly, I am pretty sure my acroporids would have suffered from slow tissue necrosis. I am not a chemist, but based on my experience and observations, sudden upward spike in alkalinity is more detrimental to corals than downward spike.

jda
08/29/2017, 03:07 PM
You could probably go down to 4 or 5 if you had a rock solid source of supply. However, there is no room for error there. I tried a stint around 6 thinking that it might help. No change for me... but I am just LN, not ULN.

DiscusHeckel
08/29/2017, 03:16 PM
You could probably go down to 4 or 5 if you had a rock solid source of supply. However, there is no room for error there. I tried a stint around 6 thinking that it might help. No change for me... but I am just LN, not ULN.

What do you mean by "rock solid source of supply" please?

jda
08/29/2017, 03:24 PM
I don't know. Everybody could be different. My CaRx has kept my alk right where I want it for a few decades now... rock solid supply for me.