kH too low

Adrienne

Adrienne

Well-Known Member
The kH in my month old tank is low - I am using the Red Sea test kit, and it is not increasing.

On 31/8 it was 6.7 and I added 12.5ml of reef carbonate as per the dosing instructions for 'beginners'.
instructions say to dose 5mls per 80 litres twice a week. Check alkalinity every two weeks.


Two days later 2/9 -this am, I added 20ml of reef carbonate. The kH this pm is 6.7

Advanced instructions say not to dose more than 20ml per 80 litres per day.

With my kH this low and not seemingly increasing how often would you recommend I dose and how much.

I have in the tank a trumpet coral, 1 open brain, 3 hairy mushrooms, 1 zoo, 1 xenia and a leather mushroom (thats what I think it is).
 
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Snid

Snid

Active Member
Whoa! I'm no coral expert, so my response may be way off, but Alkaline is a nutrient that various corals do need. Most recommendations are to not add any corals into the system until it has matured at least around 3 months, sometimes longer. With a month old system that is low in nutrients you may want to be extra observant of your corals. Look for color shifts, fading, and maybe even some bleaching.

I have read that some people have helped raise their Alkalinity by adding a teaspoon of Baking Soda to their Sump every day. If you can't add it to the Sump because you don't have one, maybe scoop out a cup of tank water, mix it in there, then gradually pour it back into the tank after it has dissolved.

Again, I am no coral expert, so I'd hold tight until others respond, but I'd at the very least start observing the corals closely each day, maybe make yourself a daily photo journal so you can compare them each day. ;)
 
sirrealism

sirrealism

Well-Known Member
Dont panic about the alk being so low. Just keep dosing the way you are. It will come up slow. Right now your putting enough in to keep the numbers ok. The truth is its not about having the perfect 8.2 alk. its more about having consistant numbers. Your doing fine. just keep going slow. Also do an extra water change. Also can you find another test kit? Got a friend who is into reefing? Take a sample to a LFS and let them test it. You might have a bad test kit.
 
pablomay28

pablomay28

Well-Known Member
Get a Hanna checker. I tried the red sea and API test kits and the color change was confusing. The checker does the work for you and is very acurate
 
reefer gladness

reefer gladness

Well-Known Member
Before we go much further with the dosing discussion - how often and how large are your water changes? In a tank without many corals it's often possible to maintain good reef chemistry with water changes alone.

Calcium carbonate will be used by various things in your tank like the LPS corals in your tank but also in the formation of coralline algae. My gut feeling is the water change schedule/size needs to be increased.

And FWIW, alkalinity is probably the most important thing to test on a regular basis in a reef tank. More important than calcium and magnesium IMO and should be tested at least weekly to keep alk stable.
 
D

DaveK

Well-Known Member
First most important thing, don't chase numbers. If your livestock is doing good, and growing, don't use a bunch of additives to get to a number.

Yes corals do deplete the water of calcium, alkalinity, and at a much slower rate magnesium. You do want to keep up on water changes.

Make sure your test kit is good. The Hana stuff mentioned is good but expensive, so you might want to try another brand of test kit first.

Be sure to test your new water too. It's not at all unusual for new water to be off by the same amount of your existing tank water. In some cases you might want to use a different brand of salt.

There is a close relationship between alkalinity, pH, calcium, and magnesium. In some cases if one is off, it is very difficult to change the others.

You SG must be correct before you do your tests. The difference between water at 1.020 and 1.025 will skew your readings by about 20%.

Here is a good article on the whole subject (offsite) - http://www.advancedaquarist.com/2002/11/chemistry
 
sirrealism

sirrealism

Well-Known Member
Not sure why people think hanna is expensive. http://www.amazon.com/dp/B005FH2O6G/?tag=reefsanc-20 and refiles are 7.29$ Yes there are cheaper ones but once you use one of these you wont go back
DaveK I agree with everything you said other then the that the Hanna is expensive. I know 42$ is more then some others but the refiles make up for it in the long run
 
D

DaveK

Well-Known Member
sirrealism said:
Not sure why people think hanna is expensive. http://www.amazon.com/dp/B005FH2O6G/?tag=reefsanc-20 and refiles are 7.29$ Yes there are cheaper ones but once you use one of these you wont go back
DaveK I agree with everything you said other then the that the Hanna is expensive. I know 42$ is more then some others but the refiles make up for it in the long run
Click to expand...

Not trying to give you a hard time, but a Sailfret KH/Alk test kit is about $14.99 on Amazon. That a whole lot less expensive than the Hana Checker at 47.79. If your willing to setttle for API you cab get a KH test kit for 4.02. Yes, the Hana device is better, but to msny it's not worth 3X to 11X the price?
 
Adrienne

Adrienne

Well-Known Member
Thanks for your replies and I will try and give the most accurate answer I can to your questions.

Water changes 10% weekly although I did an extra 15% one this morning as I have constant dust algae over the tank glass, which if I just wipe it off reattaches pretty much instantly. This morning I put the cleaning sponge over the syphon and as I wiped it pulled the excess algae up through the syphon and into the waste water container.

Salinity is 1.025 (pretty much constant as I have an auto top off unit)

kH as mentioned although I can only produce a yellow/orange colouring - never a colour as the image shows and never a deep orange.

Ca is high - 460 it turns a purple colour and around 520 more blue

Salt is Dupla Marin http://www.livingreef.co.nz/p/86/saltwater-aquarium-marine-salt

Hanna checkers are about $120 here in NZ but I am open to purchasing off the internet :)

I'll give my lfs a call and see if they are willing to do a test for me. Will report back later today.

As far as I can tell my corals are happy but being a beginner I might be missing something.
 
reefer gladness

reefer gladness

Well-Known Member
High calcium will drive alkalinity down, 520ppm is definitely too high. The salt you are using claims it mixes at 8.0 dKH and calcium at 420ppm. I would start by testing the freshly pre-mixed water and be sure it's close to these claims first. You don't dose anything to increase calcium right?

What test kit are you using? That calcium result is suspiciously high, if you can get your LFS to double-check your test results that would be helpful also.
 
pablomay28

pablomay28

Well-Known Member
Adrienne said:
The kH in my month old tank is low - I am using the Red Sea test kit, and it is not increasing.

On 31/8 it was 6.7 and I added 12.5ml of reef carbonate as per the dosing instructions for 'beginners'.
instructions say to dose 5mls per 80 litres twice a week. Check alkalinity every two weeks.


Two days later 2/9 -this am, I added 20ml of reef carbonate. The kH this pm is 6.7

Advanced instructions say not to dose more than 20ml per 80 litres per day.

With my kH this low and not seemingly increasing how often would you recommend I dose and how much.

I have in the tank a trumpet coral, 1 open brain, 3 hairy mushrooms, 1 zoo, 1 xenia and a leather mushroom (thats what I think it is).
Click to expand...

A fellow reefer recommended using baking soda to make sodium carbonate by placing it in the oven. I also had low kH and looke into making my own mix to bring kH up. I found a solution in using 1cup sodium carbonate by putting the baking soda (sodium bicarbonate) in the oven at 350 for 45 minutes and 1/8 cup of baking soda (sodium bicarbonate) into 1 gallon of RODI water. I found this information on a bulk reef supply video and this mix does not fluctuate ur pH as sodium carbonate would by itself. This has been working for me since a 1lbs box of baking soda cost less than $1 compared to the sea chem 500ml i was using for $7. In regards to the test kit prices you get what you pay for and i got tired of color matching and not being sure. Some of the other color test kits are good but the kH ones leave to much room for error.
I dose 30ml a day of the solution i make and it keeps my dkH at 8.75-9 in my RSM 250 with mixed coral. Remember when dosing you want to go up no more than 1dkH to 1.4dkH a day. If interested in making the same solution i made look up how to vids in youtube
 
Adrienne

Adrienne

Well-Known Member
Okay
The LFS confirmed my readings of kH. I didn't get the calcium checked though.

I am using Red Sea for kH, Dupla marin for CA and Mg. For the Mg I guess it depends on when the colour changes or when it actually goes blue. Once I am out of the Reef carbonate I will very likely get my own made, hubby and son are both chemistry/physics backgrounds. On Saturday when I make up the next batch of asw I will test.
 
C

Corvus

Member
Good luck! I'd say pick a test kit and stick with it. After a while I was getting all confused about what test kit to purchase, so I made a call and am glad I did.

Keep us posted on how things turn out.

C.

PS I think I will make my own sodium carbonate, too, just in case I need some.
 
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