dKH problem in my Reef Tank. Your help is appreciated.

Grumpy Bass · Nov 30, 2011

Hi,

I have a very weird problem that I would appreciate any and all thought on please.

My Alk (dKH) is too low in my tank, its currently reading dKH of 6-7. I normally run it at 10. Reading of the effluent (dKH) out of my reactor is only 11, it is usually around 24. As there is a correlation betweek Alk and Calcuum (Calcium Carbonate) that I assume if the dKH is ok... life is ok. I was gone for ~ 2 weeks, my last reading was ~10. This issue is compounded by the fact that my Calcium and Magnesium are also very high, 500 and 1450 respectively. With the calcium being so high it does'nt make sense that the dKH is so low. Please read on.

Test on Friday when I added a new C02 tank and noted very low Alk readings and high Calcium and Mag readings too.

These findings makes no sense at all to me so I am asking for help please.

Current Tank Parameters;

155 Gallon Tank. With sump a total of ~190 gallons.

Calcium is reading 500
Magnesium is reading 1450
Alk (dKH) is 7 in the tank
Alk (dKH) out of my reactor is 11
pH: 8.3
Nitrates: 0 (as measured with test kit, prob not 0 but close)
Phosphates: 0 (as measured with test kit, prob not 0 but close)
Ammonia: 0
Salinity: 1.025
Temp: 78-80
Silicates: Not tested
Iodine: Not tested

What's changed...

1 week ago: New C02 Tank (5lbs), this is when I noticed these issues so I'm assuming they are not related.

45 days ago: New Sicce Pumps, Voyager 4 1600 gph (replace defective Hydor 1400 gph pumps)

3 months ago: One (1), 60 gallon water change

6 months ago: One (1), 60 gallon water change

6 months ago: Switched to Instant Ocean, Reef Crystals (from Tropic Marin Reef Pro)

6-9 Months ago: I use ARM media in my calcium reactor but las January I switched from the pebbles to the larger media.

I have purchased another new API dKH test kit, no change so it's not the test kit. I verified the Calcium readings using two (2) kits, Salifert and Red Sea. I only have a Salifert kit for Magnesium but tested it three (3) times.

I have lowered the effluent output to reduce introduction of additional Calcium & Magnesium at the cost of again lowering the dKH. I can tell you that the effluent dKH is up over the past few days with the reduced drip rate (maybe 10 drips/min). I can consider using sodium bicarbonate but something else is going on and before I start changing or adding anything I would like to ask for thoughts.

I'm going to re-calibrate my pH probe now (let you know if it was off).

I'm going to search on-line on how to create a sodium bicarbonate dKH calibrator, let you know what it reads.

The ONLY thing I can possibly think of is that due to the high calcium readings... that maybe I have (undetecable) calcium carbonate precipitation in the system which I guess in theory could lower the Alk of the reactor & system as a whole. Maybe even though my effluent rate was good for a long time (> 2 years) that for some reason the calcium use changed / slowed down and then caused the precipitation problem? Struggling with what else this could be.

Any and all help is appreciated please.

Sincerely,
Grumpy (John L)

Murfman · Nov 30, 2011

Salinity is probably 1.025 ;-) Alk of 7 is on the low end but not terrible. Calcium reactors put more alk into your tank and a Kalk reactor puts in more Ca. Get rid of the API and use Salifert.

Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com

My calcium has been over 500 for the last few months. As long as you don't see precipitation in the tank and on equipment, I wouldn't worry.

reefsnreefer · Nov 30, 2011

well if growth stopped for a short time for some other reason and your reactor continued raising calcium, it would raise calcium while forcing alk to drop, right? You just need to re-alter settings i would imagine.

Grumpy Bass · Dec 1, 2011

OK Experts..... Any thoughts? I know the best of the best are here at Reef2Reef!

Thank you murfman and reefsnreefer for your comments.

I really hope that other experts here can PLEASE help my understand What happened and Why. I really believe that understand the what and why are so very important in keeping a reef system. I'm sure I'm not the only one who has had this happen in their systems... maybe I'm the only one who does not know what or why but I'm really hoping that the other experts here can help me better understand what happend...

Are my assumptions around calcium carbonate precipitation correct? (even though there is none visible)

Did I simply over-run the reactor?

Did my reactor fail?

I'm confident its the "your don't know what you don't know" but I really need your HELP please.

Sincerely,
Grumpy

Troylee · Dec 1, 2011

what are you using for substrate in the reactor?? maybe it's making the changes??what corals do you have?? do you dose anything??

skinz78 · Dec 1, 2011

I've been helping Grumpy out Via PM and I couldn't see any other red flags so I asked him to post about this issue. How are your corals growing?

Grumpy Bass · Dec 1, 2011

Hey Troylee.. as noted above I'm using ARM large chunk media. Not sure what changes your asking about, do you mean replacing the pumps? Let me know.

My coral list is extensive, I guess it's time to make a list but I don't have one now.. I would assume there are 30+ different types, LPS, limited SPS, softies (including a 8" toadstool), clam, etc...

Skinz... nope, no notable growth except with my Clam. I continue to lose random corals for some reason (sps) and my large red Cap is dying off and turning brown (@#$%@!%) which really sucks because they (have another doing fine) usually do really great... is the Cap turning brown and bad edges an indicator that will help diagnose this?

Thanks,
Grumpy

skinz78 · Dec 1, 2011

How big is the clam and how much would you guess that I grows per month on average?

VegasRick · Dec 2, 2011

I am not really what is causing the issue is that your are having. Your dkh in the tank is low and its low coming out of the reactor. That explains the low dkh. Certain media need a slightly lower ph maybe this is the issue. Whats the ph of the effluent? Maybe you need to turn you co2 up. As for why the ca is high. Could be related to the salt mix, but really neither the ca or mg is too high, not enough to be worried about. If it was precipitating out you would be losing ca/alk in the same proportion as corals use it.

skinz78 · Dec 2, 2011

VegasRick said:
I am not really what is causing the issue is that your are having. Your dkh in the tank is low and its low coming out of the reactor. That explains the low dkh. Certain media need a slightly lower ph maybe this is the issue. Whats the ph of the effluent? Maybe you need to turn you co2 up. As for why the ca is high. Could be related to the salt mix, but really neither the ca or mg is too high, not enough to be worried about. If it was precipitating out you would be losing ca/alk in the same proportion as corals use it.

Rick now's his stuff, he's one of the guys I was hoping would chime in! He's helped me out greatly in the past.

Troylee · Dec 2, 2011

Well losing sps and a red cap turning brown means you have a phosphate issue most likey.. Also do you run carbon if so is it a every day thing??? A huge toad stool can dirty the water up pretty good...

Paul_N · Dec 2, 2011

What are you using to test phosphates? I agree with Troylee. Sounds like a phosphate problem. 500 Ca and 1450 Mag are NOT high. I always ran my system with Ca 500+ and Mag 1500-1600. Some of the test kits will show zero phosphates but when you use a meter they will come back like .1+ which is too high. .03-.05 is the range you want. What and how much are you dosing for alk?

VegasRick · Dec 2, 2011

Could be phosphates or could be the swing in alk or could be a combination. If the alk is 7 now what was the low. Low alk could explain it all. Stability is key.
As for phosphates are there any signs? Increased growth of green algae on the glass? hair algae popping up?

Grumpy Bass · Dec 5, 2011

Using a Phosban reactor with PORA PhosLock media (changed about 2 months ago with new media), I use a Seachem phosphate kit which is a colorimetric test but clearly shows zero phosphates. I understand that most of these phos tests short of the meter can give false readings so I don't put all that into them. I don't have a lot of algea, a little here and there but I don't think it's at a problem level. I guess I need to consider getting the Hana meter. Oh... I don't have any hair algae that I can see anywhere. I did buy four (4) very large snails (1.5" in dia.) which have been really cleaning things up.. wonder if their masking something...

My Alk HAS NOT been stable.. thus this post in the first place for sure. I really thought this Alk swing was the root of the problems in the system but I JUST DON'T KNOW.

Are you suggesting that the Alk swing from a constant 10 for the past 3 years... to a drop to 6-7 over the past 2-3 weeks could be the issue?

*** So If the problem is low Alk (until I can prove or disprove my Phos is above zero (0)), the problem HAS to be from my reactor.... (Right????) To that end... yesterday, I tore my Calcium Reactor down, cleaned everything and filled it with new ARM large media. During the tear-down I did find that the media in the bottom was almost mud suggesting that I had the pH too low in the reactor which might of contributed to the Alk drop (anyone agree???). I re-calibrated the pH probe too, it was off by .02 so not too bad but now its reading right on. I then adjusted the mid point to 6.8 versus 6.4 which I had before. I read a lot about where the calcium breaks down and it' s at a higher pH than I originally thought (< 7.0). The dist I bought the reactor from told me to use 6.4 as the mid-point but I know believe that was too low.

Vegas.. what do you think??

Thanks a million for all the help.
Grumpy (Not really so)

VegasRick said:
Could be phosphates or could be the swing in alk or could be a combination. If the alk is 7 now what was the low. Low alk could explain it all. Stability is key.
As for phosphates are there any signs? Increased growth of green algae on the glass? hair algae popping up?

skinz78 · Dec 5, 2011

When you get into Cal reactors you step out of my league so I can't be much help there.

One suggestion I have is I always try to change my Phosphate removal media once a month weather I think it needs it or not. Helps me remember what I have going on as I am lazy and forgetful. I'm not saying this will help with the low Alk, I'm just saying it will help with any algae problems.

Grumpy Bass · Dec 5, 2011

Hi Paul_N.. I use a SeaChem test kit, it's a standard colorimetric test kit (it reads zero (Yellow)). I will look at getting a Hana meter I guess. I'm a little concerned about the high Ca and Mag but it's really the low Alk that has me really concerned. As stated, I run a calcium reactor, no other dosing. For 3 years all as been great until the past short period of time.

I don't want to dose for low Alk until I understand what has happened because it was good for sooooooo long. I hope that makes sense.

Any additional thoughts are appreciated.

Sincerely,
Grumpy

Paul_N said:
What are you using to test phosphates? I agree with Troylee. Sounds like a phosphate problem. 500 Ca and 1450 Mag are NOT high. I always ran my system with Ca 500+ and Mag 1500-1600. Some of the test kits will show zero phosphates but when you use a meter they will come back like .1+ which is too high. .03-.05 is the range you want. What and how much are you dosing for alk?

Me z · Dec 5, 2011

Two things I notice that havnt been thrown out there yet. First was the new co2 food/beverage grade or higher?? commercial co2 has lots of impurities and can have a hard time dropping the ph in the reactor low enough to dissolve the media. Second how old is your test kit?? Do you have another kit to compare your kit to? maybe a fellow reefer in your area. Yes alk swings can be worse than any parasite or plague in a tank. It can wipe out a tank very quickly so alk swings can definatley cause what your experiencing. However with your stating that the tissue is slowly turning brown and things are randomly dying off I dont suspect the alk swing to be the culprit here. In fact I suspect your alk is higher than you think and you just have a bad test kit. I could be very wrong but its definatley an avenue worth pursuing. I would also lay off the magnesium dosing for a while. When it gets back in line buy some neomag from brightwell aquatics. It goes in your calcium reactor and does a very good job maintaining magnesium levels and its hard to get it to raise out of control this way. If you find that your alk test kit is in fact accurate (this is why I prefer salifert it comes with a reference to test your kit) Look up randy's recipe and start dosing alk until it comes back up to normal levels it will raise your alk without raising your calcium, in fact most likely your calcium will drop back into proper ratio's with the alk. I wish you luck if you wish to pick my brain please feel free to pm me. Im not a chemistry gu ru but im not the average bear either. :bigsmile:

Grumpy Bass · Dec 6, 2011

Me z... So I purchased a second API dKH test kit and get the exact same results so unless multiple batches of the dKH test kits are bad it's not the kit (the dKH are simple kits). As for reducing the dosing of Mag... I ONLY use my Calcium reactor and I have already cut it way back to try and raise the Alk effluent output so this will reduce the Calcium and Mag additions.

I too think there are seperate things going on.. My Alk has dropped and I still have no idea how or why. (@$!@#$!#@$) The secondary issue might be Phosphate levels are actually higher than I think.

So today...

1. Replaced the phosphate media with new PORA PhosLock.

2. Purchased Hanna Phosphate colorimeter (+ extra reagents), Hanna Calcium colorimeter (+ extra reagents), Hanna Nitrate colorimeter (+ extra reagents) and Hanna Alk colorimeter (+ extra reagents)..

I hope buying these digital testers will put an end to "Are my numbers really accurate".

Thanks Me z.. I will take all the suggestions everyone has... the minute I stop listening is the second I stop learning!

Sincerely,
Grumpy

Me z · Dec 6, 2011

Its really strange that your magnesium is elevated with only using a calcium reactor unless you have a media like neomag in there along side the normal media to maintain magnesium levels. I am not familiar with the media your using maybe they put some form of magnesium supplementation in it?? I will be following your thread closely I am very intrigued to see what you uncover. Keep us posted with your test results from your new meters.