Lowest dkh for sps.

[YumaMan]

I read somewhere that if your ALK is high (say 9.0) then you are fine as long as your Ca is high (say 490) and your Mg is high (say 1450).But if your ALK is low (7.0) then you are fine as long as your Ca and Mg are correspondingly low. Any truth to this rule?

 

[Dana Riddle]

Just started adding some acro frags to my tank which has been running about 7 months now.

added them two weeks ago, look fine. Checked my alk today and it’s 6!

Used Hannah, and salifert. Instant ocean salt, I don’t have any coraline or many corals (10 frags ) in this 180.

not sure where all the alk is going. Chaeto, phosgard?

I haven't waded through all 3 pages of this thread, but phosphorus-removing compounds can deplete alkalinity. With that said, the alk in my tank has never dropped below 7.

Product Review: Two Little Fishies’ Media Reactor 150 and PhosBan Phosphate and Silica Adsorption Media

TLF's 150 Reactor and PhosBan media performed as advertised. Under the conditions of this testing, both phosphate and silica concentrations fell to levels below the detection limits of 'laboratory grade' instruments. The successful application of these products in aquaria around the world is a...

reefs.com

 

[DiZASTiX]

I’m not sure if you checked your salinity. But if you mix with a lower salinity that may be why. Recheck your Refractometer and recalibrate?

This, also. Paraphrasing what Austin Lefevre says, you don't want to convert your reef tank into a freshwater reef.

 

[Randy Holmes-Farley Verified Community Expert]

Silly question, but can I just add straight baking soda to the sump, or does it have to be mixed up in RO water first before going in?

You can add it directly, but the risk is two fold and it is best to dissolve it:

1. Local precipitation of calcium carbonate around the particles as the very high local alkalinity induces precipitation

2. Granules may get to delicate organisms and land on them before dissolving.

 

[Randy Holmes-Farley Verified Community Expert]

I had no idea this occurs. I may consider adding some ever clear to my alk solution. I'm going to have to look into how it would effect solubility.

Edit:based on solubility I think another route would be better.

The effect is when nitrate is consumed, which offsets the alk lost when the ammonia is converted into nitrate.

note: if your nitrate is steady, there will be no effect of carbon dosing on alk. It is only if it causes your nitrate level to decline. A drop of 50 ppm nitrate will add about 2.3 dKH of alk.

I go over the exact reasons in more detail here:

http://reefkeeping.com/issues/2004-12/rhf/index.htm

 

[FishTruck]

I have "discovered" low Alk (usually 6) many times... and generally it doesn't seem to bother the corals at all - but - rapidly pushing it up to 9 or 10 will definitely bother them.

Running at 7 seems to be the sweet spot for me using IO salt.

 

[Phildago]

The effect is when nitrate is consumed, which offsets the alk lost when the ammonia is converted into nitrate.

note: if your nitrate is steady, there will be no effect of carbon dosing on alk. It is only if it causes your nitrate level to decline. A drop of 50 ppm nitrate will add about 2.3 dKH of alk.

I go over the exact reasons in more detail here:

http://reefkeeping.com/issues/2004-12/rhf/index.htm

I get a bit crazy with numbers when I measure, so I've been avoiding it. By eye I can tell that I'm higher than normal due to algae growth though. It makes sense because I just started feeding much more.

Do you think sugar or vinegar would effect the solubility of my dosing solutions? I used to carbon doss, became algae free for a long time so I stopped, but now I dose trace elements and don't have a free dosing pump, so I'm trying to work around that issue by mixing two together.

 

[Reef-Masters]

Hello all, I didn’t see your PO4 numbers...45 fish isn’t that big of an issue in your 180 assuming there is sufficient turnover and you are not over feeding, or else you wouldn’t have 45 fish.

That said, we typically run our 350 gal frag grow tanks at 8.5-9 dkh and maintain 35.5-36 salt, 79-80 deg, phos at .00-.06, no filter socks, water changes VERY infrequently. We grow large amounts of Chaeto in our refugium which acts as a bio filter.

In short, you should not be wet skimming...imo. Many people over skim. Our 180’s have skimmers and no socks. We empty the collection cups maybe every two months...there’s only about 1”-2” of skimate in a 5” deep collection cup and it is more sludgy than liquid. In our larger 350 gal systems we drain off 5 gals of skimate every 2.5-3 months. In reality you NEED some of this biological matter in the water to sustain a healthy bacterial biome. When you don’t allow your bacterial levels to match your feeding regimen and waste production, you will FOREVER chase PO4, nitrate, nitrite, etc...we set our skimmers to where the bubbles pop in the throat of the skimmer, not up in the cap!

Try to get your temp to 79-80 THEN CHECK SALINITY as the specific gravity changes with each degree of water temp, then adjust accordingly over a weeks time. Once your salinity is right, check Ca and adjust to get the 425-500 (though you should not be consuming Ca with a few sps and insignificant coraline). You should be able to maintain a healthy system once your bacterial colonies adjust.

 

[RedSea500MaxS]

As I have commented many times.....and will keep on it:

NEVER ADD WATER TO TANK BEFORE TESTING IT.

I caught a batch that was 510 CA, another that was 12 DKH. Tech doing my water change said ...."I had never before thought to check his make up water before water change". His tank was over 530 CA, and 11 DKH. he wonder why corals were doing so poorly.

And as we know, different salts use different targets with some as high as 11DKH, some low.

 

[Randy Holmes-Farley Verified Community Expert]

In short, you should not be wet skimming...imo. Many people over skim. Our 180’s have skimmers and no socks. We empty the collection cups maybe every two months...there’s only about 1”-2” of skimate in a 5” deep collection cup and it is more sludgy than liquid. In our larger 350 gal systems we drain off 5 gals of skimate every 2.5-3 months. In reality you NEED some of this biological matter in the water to sustain a healthy bacterial biome. When you don’t allow your bacterial levels to match your feeding regimen and waste production, you will FOREVER chase PO4, nitrate, nitrite, etc...we set our skimmers to where the bubbles pop in the throat of the skimmer, not up in the cap!

I don't agree that one should not wet skim, nor am I sure it is possible to overskim in general.

I do agree that nitrate and phosphate should not be driven too low in most tanks, regardless of how it is coming about.

 

[Randy Holmes-Farley Verified Community Expert]

As I have commented many times.....and will keep on it:

NEVER ADD WATER TO TANK BEFORE TESTING IT.

I caught a batch that was 510 CA, another that was 12 DKH. Tech doing my water change said ...."I had never before thought to check his make up water before water change". His tank was over 530 CA, and 11 DKH. he wonder why corals were doing so poorly.

And as we know, different salts use different targets with some as high as 11DKH, some low.

Wow, pretty big font. lol

That said, 530 ppm calcium is not any concern (IMO).

11 dKH might be a concern if you have low nutrients and SPS.

neither value would have been outside where I wanted to keep my tank, nor is it outside of the expectations for many sat mixes.

 

[RedSea500MaxS]

What is the lowest for SPS? And what advantage or disadvantage is lower DKh? Isn't natural seawater around 7?

So, what is optimum? What does higher or lower do for our SPS?

 

[Randy Holmes-Farley Verified Community Expert]

What is the lowest for SPS? And what advantage or disadvantage is lower DKh? Isn't natural seawater around 7?

So, what is optimum? What does higher or lower do for our SPS?

Seawater alk is a bit below 7 dKH.

Higher alk often gives faster growth for some hard corals, but if there is not adequate nutrition to allow tissue to keep pace with skeletal growth, one may get burnt tips on some SPS.

lower alk (say, 7 dKH) allows you to keep lower nutrients so the brownign tha tmay come with higher nutrients and hence increased zooxanthellae may not happen.

So in really simplistic trams, it may be a trade off between color and growth.

 

[RedSea500MaxS]

Wow, pretty big font. lol

That said, 530 ppm calcium is not any concern (IMO).

11 dKH might be a concern if you have low nutrients and SPS.

neither value would have been outside where I wanted to keep my tank, nor is it outside of the expectations for many sat mixes.

Agreed....where do you like to keep your tanks Randy? My comment is if your trying to keep a consistent 8.3 DKH and 430 Ca, and your water change is using 12 DKH and 510 Ca, it might be why some people like me hated water changes....everythiug was fine now my corals are ticked.

Thank you....I am using only common sense, I bow to you as an expert. How we learn....a lot of info out there and we need some solid facts, rules, and focus on what we need instead or 8, or 7, or 11, or???? My head hurst trying to know "what is best". we appreciate help like yours to establish some best practices.

Thank you

 

[FishTruck]

Seawater alk is a bit below 7 dKH.

Higher alk often gives faster growth for some hard corals, but if there is not adequate nutrition to allow tissue to keep pace with skeletal growth, one may get burnt tips on some SPS.

lower alk (say, 7 dKH) allows you to keep lower nutrients so the brownign tha tmay come with higher nutrients and hence increased zooxanthellae may not happen.

So in really simplistic trams, it may be a trade off between color and growth.

I have low nutrient tank and experienced this with my ALK = 6 discoveries. I have a red planet that becomes multicolored and gorgeous when I neglect the tank and the ALK drifts down. In the past... thinking that the ALK 6 was just too darn low (despite the apparent optimal health of my corals).... I dosed it up - watched my green slimers get burned tips and die... and my red planet all turned a boring maroon color. It takes my corals three to six months to recover from these events. I only had to repeat this mistake like five times before I finally realized what was going on.

 

[Popkorn0407]

I use Aquaforest salt and keep the parameter of the salt at 35ppm the more stable possible. 8.4 /8.3 dkh for me is the best range.

 

[Wildreefs]

Randy:

What should my game plan be in the scheme of things:

I keep a lot of angels, 12 of them. LPS are a no go for me. Only looking to keep sticks and montis. Being I have so many fish, Hugh nutrients are inevitable for me. About 180 gallons of water volume , I do a 50 gallon change every week.

I’m going to be producing a lot of nitrates (if more fish equals more nitrate) but even in smaller bio loads, if you’re only changin our 30 percent or so of water a week, and not 100 percent, you’re never going to 0 out and restart, so that number is going to climb regardless of fish amount I would think, just a bigger scale .

Running chaeto, good skimmer. Still if my nutrients are high, should I be slowly aiming for higher alk? Was at 6 two days ago, dosed your two part (just the alk part of it) and I’m at 7 and change now. Also, lighting wise, should I be looking to bast them with ore food in the water?

 

[Wildreefs]

I haven't waded through all 3 pages of this thread, but phosphorus-removing compounds can deplete alkalinity. With that said, the alk in my tank has never dropped below 7.

Product Review: Two Little Fishies’ Media Reactor 150 and PhosBan Phosphate and Silica Adsorption Media

TLF's 150 Reactor and PhosBan media performed as advertised. Under the conditions of this testing, both phosphate and silica concentrations fell to levels below the detection limits of 'laboratory grade' instruments. The successful application of these products in aquaria around the world is a...

reefs.com

Is 7 a good place to be with I’m high nutrients? Many fish, mostly angels, no LPS, using 3 radions xr 15s with 4 60 inch t5 bulbs 6 hours a day. (Aquatic life t5 hybrid)

 

[Wildreefs]

You can add it directly, but the risk is two fold and it is best to dissolve it:

1. Local precipitation of calcium carbonate around the particles as the very high local alkalinity induces precipitation

2. Granules may get to delicate organisms and land on them before dissolving.

Ok I mixed it up in gallon of Ro like recipe 1 states. Not all dissolved, when I poured solution into tank, near return pump, return nozzle looks like it blew out a few seconds of micro bubbles. Assuming this was non dissolved alk, let’s say best case scenario it all went to sand bed instead of landing on corals, will it eventual dissolve and become part of the water , or will it just lay on bottom like sand particles?

 

[RedSea500MaxS]

Randy:

What should my game plan be in the scheme of things:

I keep a lot of angels, 12 of them. LPS are a no go for me. Only looking to keep sticks and montis. Being I have so many fish, Hugh nutrients are inevitable for me. About 180 gallons of water volume , I do a 50 gallon change every week.

I’m going to be producing a lot of nitrates (if more fish equals more nitrate) but even in smaller bio loads, if you’re only changin our 30 percent or so of water a week, and not 100 percent, you’re never going to 0 out and restart, so that number is going to climb regardless of fish amount I would think, just a bigger scale .

Running chaeto, good skimmer. Still if my nutrients are high, should I be slowly aiming for higher alk? Was at 6 two days ago, dosed your two part (just the alk part of it) and I’m at 7 and change now. Also, lighting wise, should I be looking to bast them with ore food in the water?

Need to see some pics....love our angels.