Constant Low Alkalinity

[Zalman]

As the title states... my tank seems to be suffering from constant low alkalinity issues. I have a roughly 320 gal system - 180 tank, 75 fuge, 150 sump - fuge and sump arent filled to the top. I use Reef Crystals and do 50 gal water changes every other week.

My DKH has always been low since I started this tank. It would always be somewhere around 6-7. My tank evaporated somewhere around 3-5 gallons per day and I have a kalkwasser reactor dripping 24/7 into my tank. I recently added some new fish to my tank and replaced my skimmer and started vodka dosing to cope with the increased bioload (nitrates did skyrocket before I got my new skimmer running). Ever since my DKH has tested around 5 and I cannot seem to raise it above that. I have tried larger more frequent water changes - 100 gallons every 7-9 days. Still no change. Any suggestions on ways to raise my DKH to more acceptable levels?

PH - 8.2-8.4
DKH - 5
Calcium - 380-400
Mag - 1280

 

[Buzz1329]

Soda Ash (Sodium Carbonate) and/or Bulk Sodium Bicarbonate available at:

http://www.bulkreefsupply.com/bulk-...ash-sodium-carbonate-aquarium-supplement.html

 

[Zalman]

So would I use that instead of the calcium hydroxide? and can I match the evaporation rate like I do with the Kalk reactor? Or are there dosing instructions I am unaware of?

Also could I just use my kalk reactor and fill it with sodium carbonate or bicarbonate instead?

 

[Dr. Reef]

u need to dose sodium carbonate or bicarbonate slowly into the tank. they both have temp high or low ph respectively.
i used to dose it with a doser. in a gal of ro/di water mix as much the calculator told me to put in teaspoons. i use BRS calculator.
so for example: i have a 300gal system and current alk is 7 and i want 8, plug the numbers in the calculator and it will tell u to put 7 teaspoons of sodium bicarbonate.
so i mixed 7 teaspoons in 1 gal rodi water. then with the help of a doser dosed it with intervals over 24 hrs.

 

[Zalman]

Oh wow... I completely missed the calculator on their site - my apologies. Do I have to use a doser? or could I pour like 1/4 gallon into the tank 4 times spread out through out the day? Sorry for all the questions, I dont want to mess anything up worse than it already is.

 

[Dr. Reef]

Oh wow... I completely missed the calculator on their site - my apologies. Do I have to use a doser? or could I pour like 1/4 gallon into the tank 4 times spread out through out the day? Sorry for all the questions, I dont want to mess anything up worse than it already is.

no dont be sorry, if u dont ask u will be sorry for real lol...
no need for a doser. i had one i utilized it. u can calculate the amount of powder to be used and make sure u set the units correctly i have made mistakes several times between meq/l or dkh or ppm.
but yah u can pour it after mixing it in rodi water over time.

NOTE: i used a gal of water, you dont have to use that much u can also use as low as few cups of water to dissolve all the chemical in.

 

[Dr. Reef]

forgot to mention dont increase alk more than 1.5dkh per day.

 

[Dr. Reef]

from BRS website:

"INSTRUCTIONS

Fully dissolve the Sodium Bicarbonate in RO/DI or distilled water. Slowly add the solution to high flow areas of the tank and avoid directly blasting corals with the concentrated solution. Sodium Bicarbonate will have a very slight, temporary lowering effect on pH. Avoid increasing alkalinity levels more than 0.5meq/lt or 1.4 dKH per day, if necessary spread the suggested dose out and test between doses.

MIXING NOTES

When mixing the salts with the filtered water it is best to add a small portion at a time, shake the jug and add more so the salts don't clump up. If it does clump, float the jug in hot water to warm the fluid inside and it should dissolve easier. We recommend allowing the solution to rest at least a couple hours before use so the salts have a chance to fully dissolve. "

 

[bertoni]

Many tanks require daily dosing, even with Kalkwasser. A 2-part is an easy way to get going. Corals consume calcium and alkalinity in a fairly fixed ratio of 20 ppm Ca⁺⁺ to 2.8 dKH, so dosing both usually is appropriate. It's harder to see the drop in calcium because there's so much more of it in seawater.