Help With Alkalinity

[MD Ocean Girl]

Hi All!

Jesse and I are having some problems with our 40 gallon long mostly SPS tank. The past few months, a lot of our SPS and chalices have bleached. Some of the corals are almost completely white. They still have polyps, so I know they're not dead. The rest of the corals that aren't bleached are growing extremely quickly.

We've done multiple things to the tank in recent months.
1. We have a 6 bulb 54W T5 light over the tank. We replaced 3 bulbs, putting in 2 Giesemann Actinic + and 1 Pure Actinic. The light now has 3 of the Actinic +, 2 Pure Actinics, and 1 Aquablue +. We made the switch to only one Aquablue + because certain corals (like our Todd's torch) were browning out from too much light. It looks much more green now.

2. We bought a reactor from BRS, and started running GFO on the tank. We only used 1/2 of the recommended amount, using the BRS calculator. We had also been running carbon in a mesh bag in the filter sock of the sump, but also put that in a reactor as well (also at 1/2 of the recommended amount). Both the GAC and GFO are from BRS.

3. We removed 1/3 to 1/2 of the sand bed. The tank had a deep sandbed, but since our jawfish died, and the watchman goby is in our 40 gallon breeder, there really was no need to keep a deeper sandbed. The sandbed is now right at the height of the black trim on the bottom of the tank (maybe an inch)?

4. Removed the glass tops and hooked up a small computer fan that turns on when the daylight bulbs kick on for 4 hours. This was done to help regulate tank temp (the tank was getting close to 82 degrees when all 6 bulbs were on).

These changes were made to help battle a little bit of stubborn hair algae we can't seem to get rid of, even with manual removal. The tank parameters at these changes on 5/15/12 (and yes, they stupidly were done all at the same time) were:
SG: 1.026
pH: 8.2
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 0 ppm
Phosphate: 0 ppm
Calcium: 500
Magnesium: 1230
KH/Alk: 8.3 dKH, Alk = 2.97 meq/L
* All tests are API test kits except for magnesium and KH, which are Salifert.

After all of this, corals started bleaching. We do weekly water changes, make our own RO/DI water (TDS from membrane is 3, TDS from DI is 0). Hair algae is still there. I've been thinking the problems could be due to low alkalinity, so I decided to test the tank. (The tank has the man made reef-ready rock in it, if it makes any difference).

Last night's test (7/14/12):
Temp: 77.9 F
SG: 1.025
pH: 8.2
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 0 ppm
Calcium: 480
Magnesium: 1380
KH/Alk: 4.8 dKH, Alk = 1.71 meq/L

I've been reading up on dosing since last night, but I'm looking for some help on what to do to fix the problem. The calcium isn't too high, which makes the very low alk reading a bit confusing. Should I use sodium bicarbonate to raise the alkalinity, or should I go buy 2-part and use that? Or something different? Jesse and I have never had to dose anything in any of our tanks before, and don't have any automatic dosers on hand.

Is there any way the bleaching issue could be caused by more than just a low alkalinity? We did make a lot of changes at once, so it's hard to say if just one of them could be a cause. I don't know if the corals aren't getting enough light now, or if the carbon and/or GFO stripped too many essential nutrients from the water.


I figured I'd ask the experts here before I'd post over in the reef chemistry forum. Any help at all would be greatly appreciated. Thanks so much in advance!!

 

[Gary Majchrzak]

wow

wow

are you sure that alk reading is right?

I know GFO depletes alkalinity.... as do calcifying organisms.
Your Ca is obviously fine.

You can use Arm & Hammer baking soda to make a liquid alkalinity supplement.
(This is what I use for a liquid supplement).

I bake a box of A&H baking soda at 300F for one hour and mix it into a gallon of RO water. Follow Randy's recipe. This is essentially the same thing as B-ionic alk but MUCH CHEAPER.

Add this slowly over time because it will raise pH !

 

[MD Ocean Girl]

Gary, I checked the reading twice. I also ran a test with the test solution that came with the kit. The test solution has a dKH of 7.2 +/- 0.3. I got a reading of 8.3 dKH. I KNOW that I'm doing it right, so maybe my test kit is bad? It says it doesn't expire until 2015......

I'm going to run out to ABC as soon as they open and have Jeremy retest my water. If the alk is really that low, then it's off to the grocery store to get some baking soda. I'll google Randy's recipe in the mean time.

If the alk is that low, and I use baking soda to raise it, how much should I add at a time? And can I just add a bit in at once, or should I be dripping it in?

Thank you!

 

[Gary Majchrzak]

there are two or three online dosing calculators somewhere... I'll see if I can locate at least one of them.

BRS website has one. Randy's article has a link to one...

I don't doubt that alkalinity can become THAT depleted... especially if you reduced PO4 with GFO. This will directly and indirectly have an impact on alkalinity.

 

[Gary Majchrzak]

BRS calculator

PS: BAKED baking soda is sodium CARBONATE

UNBAKED baking soda is sodium BICARBONATE

this is the calculator I usually use

 

[MD Ocean Girl]

Gary, Thanks so much! Hopefully, correcting alk will help with the bleaching issues. :headwallblue:

 

[Jstn]

Gary, I checked the reading twice. I also ran a test with the test solution that came with the kit. The test solution has a dKH of 7.2 +/- 0.3. I got a reading of 8.3 dKH. I KNOW that I'm doing it right, so maybe my test kit is bad? It says it doesn't expire until 2015......

I'm going to run out to ABC as soon as they open and have Jeremy retest my water. If the alk is really that low, then it's off to the grocery store to get some baking soda. I'll google Randy's recipe in the mean time.

If the alk is that low, and I use baking soda to raise it, how much should I add at a time? And can I just add a bit in at once, or should I be dripping it in?

Thank you!

One uses sodium bicarbonate if your ph is high, it is mildly acidic compared to its carbonate partner.

 

[cardiffgiant]

I personally try not to raise by more than 0.5 dKh per day. The BRS calculator is good for homemade alkalinity supplements (baked baking soda) using Randy's recipe.

 

[Gary Majchrzak]

One uses sodium bicarbonate if your ph is high, it is mildly acidic compared to its carbonate partner.

good point, Justin.

Since her pH is 8.2 and she needs to boost alkalinity A LOT it would probably be wiser for her to use sodium bicarbonate right now.

 

[Jstn]

good point, Justin.

Since her pH is 8.2 and she needs to boost alkalinity A LOT it would probably be wiser for her to use sodium bicarbonate right now.

Agreed, in addition like ben said, it would be wise to do it slowly; Alk swings in any direction can be bad.

 

[MD Ocean Girl]

Thanks, guys.

I just picked up some baking soda. I won't bake it. I'm going to mix it up using Randy's recipe, and slowly add some to the tank. I'll use the calculator to stick to 0.5dKH a day. I'm hoping that this will help the issues, and I won't kill anything in the process.

 

[Flanders]

Did you say you normally don't dose anything? If so, then you should start dosing something regularly to replace depleted calcium and alkalinity, or these problems will continue.

 

[MD Ocean Girl]

Did you say you normally don't dose anything? If so, then you should start, or these problems will continue.

Yep, we normally don't dose anything. We've never needed to. Water changes were enough to keep everything where it needed to be. This tank was a mixed reef. It's only become a SPS heavy tank since we set up the 40 breeder 4 months ago. The other 2 tanks (40 breeder is a softie/anemone tank, and my 10 gallon is a mixed reef) haven't had any issues with bleaching, etc.

 

[Flanders]

You really do need to, though. Unless you're doing full 100% water changes your levels will gradually creep down. As your corals uptake calcium, etc. in their skeletons they deplete your water to below NSW levels. Your water changes cannot mathematically keep up (unless they are 100%), and I think that's why you're having these issues. I suggest a two-part or kalk dosing.

 

[iamwrasseman]

i think the sps have been consuming alk,Ca etc , and its finaly catching up to ya ! better get the water tested and see where your really at

 

[MD Ocean Girl]

Dave,

I Stopped into ABC 1 yesterday, but they really didn't have any test kits on hand. Mike did test my alk at least; it was at 5.4 dKH. I'll stop by ABC 2 on Tuesday and have you test my water for everything, just to make sure all of my test kits are accurate at this point.



I mixed up a gallon of water with baking soda yesterday, following Randy's recipe #2. Calculated out how much I would need to dose the tank with to raise alk 0.5dKH. Dosed last night, then waiting over an hr just to check levels again.

pH from the sump (where I dosed) was 8.8, but was 7.8 when I checked water from the actual tank. Calcium was at 460 (from the tank). Alk jumped up from my pre-test of 5.4dKH to 6.4dKH (water also from the tank). I have NO idea why it jumped up that high. I made sure I only added the correct amount of baking soda solution, and did it slowly. I'll test again in a little bit to see where everything is at.

Do I continue to dose today to raise the alk another 0.5dKH, or should I hold off if alk is still near 6.4dKh?

 

[MD Ocean Girl]

You really do need to, though. Unless you're doing full 100% water changes your levels will gradually creep down. As your corals uptake calcium, etc. in their skeletons they deplete your water to below NSW levels. Your water changes cannot mathematically keep up (unless they are 100%), and I think that's why you're having these issues. I suggest a two-part or kalk dosing.

I agree that I'm going to have to start dosing that tank. I should have realized that with how much SPS Jesse was adding to the tank, and how fast certain corals were starting to grow, that the calcium and alk would start to drop off fast. I was just really busy studying for a huge exam at that time, and then Jesse and I went on vacation, so we weren't paying as much attention to the tank as we should have. Lesson learned. Hopefully we don't lose more than the couple frags we already have.

After the alk is stabilized back to where it should be, I'm going to have to look for an automatic doser and start adding the baking soda solution, or two-part of kalk to the tank.

 

[Flanders]

I was always successful with just drip dosing kalk during lights out for all top-off water and then adjusting weekly from there. You can phase in manually dosing two-part if the kalk can't consistently keep up. A dosing pump is nice but not a requirement.

IME many corals really don't like low alkalinity but don't typically mind slightly high alkalinity, so I like to keep it boosted a bit higher than NSW levels to give myself some room for error.

 

[MD Ocean Girl]

So it's been about 4 months since I first posted about the low alkalinity and bleaching problem. Things in the tank are much more stable, overall. And the hair algae started to disappear as soon as I started to raise up the alk with the unbaked baking soda solution...with a little manual removal as well, the tank has been hair algae free for about 3 months!!!!!! :dance: However, we're still having some issues. Some corals are still really bleached/translucent. Others have great color. Most are growing like crazy still.

For the past few months, the tank has been basically running with an SG of 1.025, pH of 8.4, alk of 9-10, calcium of 400, magnesium of 1350, phosphates around 0.25. No ammonia, nitrites, or nitrates. Unbaked baking soda solution is added to the bucket for the ATO, which was working well to keep everything stable. Corals still weren't coloring up.

Within the last few weeks or so, the corals are still really growing (some have doubled in size in a month), but they've started to bleach more or become more translucent. I've been a bit busy with studying for my medicine shelf exam, so I basically was making sure the ATO was full and dosed, filter socks changed twice a week, and a water change done every two weeks. I started to feed the fish more, thinking that maybe the tank is now a bit nutrient poor. There's only an algae blenny, coral beauty, mystery wrasse, and blue damsel in the tank, so even when I feed, it's not a lot of food. It hasn't really been helping the corals color up at all. So I decided to test the water and do a water change last night.
Tests before water change:
SG: 1.025
pH: 8.8
Ammonia, nitrite, nitrate: 0
Phosphate: 0.5
Calcium: 300
Magnesium: 1170
Alk:12

I'm actually happy about the phosphates, because when there was all that hair algae, my phosphates always were 0. Now, I'm seeing some in the tank, but no hair algae growth. So that I think is good, because water changes will help lower the levels.
I'm going to assume the alk is a bit higher than normal because we've had to run the heat the last few weeks, so there's increased evaporation, and since the baking soda solution is added to my ATO bucket, I'm sure more is being added than necessary. I'll have to readjust how much I add to the ATO.
I couldn't believe how low my calcium and mag were! The last time I tested, they were like the first numbers I posted above. Could this be the cause of the corals still staying bleached/translucent? Or is something else still going on? I'm sure it does play a part, but even when they were within normal ranges, the corals weren't coloring up. If all the corals were doing the same thing, this would be a lot easier to figure out and treat. But some of them look absolutely amazing, and some of them look completely white, and they only reason I know they're not dead is because they still have polyp extension.

So I did a 5 gallon water change last night, added some Kent mag, and 10ml of Liquid reef from Brightwell Aquatics to raise up the calcium. I also replaced some of the bulbs in the light fixture, as they were a year old. I'm now running 2 new Geissman Aquablue +, 1 new Geissman pure actinic, and then 1 6 month old pure actinic, and 2 6 month old Geissman actinic + bulbs. I didn't like the look of having just one Aquablue + in the tank. I just don't want to add too much light now and bleach the corals any more than they already are. I'll do another water change today once I have more water made up.

Any suggestions for what else I can or should be doing to help these corals regain their color? Or is this due to some of my levels being a bit off? I'm definitely happy the hair algae is gone, but I'm frustrated that the tank doesn't look like it should. :headwally:

Thanks for all the help!!

 

[RoscoPColtrane]

That is a lot of light for a 40 gal, you may need to reduce your light period. I use a 6x39w ati fixture on my 120 and still need to be careful about bleaching new SPS. I run my blue bulbs for 10 hrs and all 6 for only 6hrs a day.