FRANK48
Active Member
I did a water change yesterday because my alkalinity was low. I’ve tested today and it is still the same and I’m confused on why it hasn’t increased. I’m using the Red Sea foundation test kit and I used Red Sea coral pro salt.
Water change alkalinity
- Thread starter FRANK48
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Miami Reef
10K Club Member
How big of a water change did you do?
How low is your alk?
What corals are you keeping?
How low is your alk?
What corals are you keeping?
Miami Reef
10K Club Member
Your alk is not low. It’s natural sea water levels.
Your salt mixes to about 8dkh which is spot on to me.
Changing only 12% of your water won’t give you that alk boost you are hoping for. Time to start looking into 2 part or kalkwasser supplements if you wish to maintain higher levels.
The corals you are keeping don’t consume a large amount of alkalinity, so start slow with your dosing.
Miami Reef
10K Club Member
I’m very fond of 2 parts. Put simply, there’s 2 solutions: one calcium and one alkalinity.
You dose the same amounts (in mL) every day. Works best with an auto doser.
I like the dosers where you input how many mL you want dosed per day, and it will split that dosage into smaller amounts throughout the day.
I do recommend keeping alk from about 7-9 dkh. Some people go as high as 12dkh, but I personally see more negative effects to corals at that level.
Miami Reef
10K Club Member
Start at 1-2mL per day and test weekly. If it’s too low, raise by 1-5mL, if it’s just right: don’t change dose, then test the next week etc.
That’s how I’ve always done it and it leads to an extremely dialed on system. The goal is for the corals to consume more and more alkalinity over time. As they grow, their alk demands will increase. More alk consumed = more coral growth.
Neon_Devil
Community Member
The back of the bottle usually has the instructions. I'm assuming you're new to reef keeping?
Miami Reef
10K Club Member
You will find that doing water changes will have very little effect to your alkalinity. The percentage of 10-15% a week has negligible effect your alkalinity levels.
I personally would keep a goal alk from anywhere between 7-9 dkh and not worry about matching your salt mix to you tank when doing your weekly water changes.
Miami Reef
10K Club Member
Nope. You continue dosing the same amount per day.
Let’s say you require 5mL per day to maintain 9dkh. You will dose 5mL every single day but you will notice the dkh will slowly drop lower and lower throughout the weeks even though you are doing the same amount, so then (for example) you will need to dose 6mL to maintain the same level of 9dkh.
All that’s changing is that the corals are consuming more alkalinity. So now you need to dose more to maintain your level. It’s a good thing.
Miami Reef
10K Club Member
I personally would. I think 8 dkh is a good goal to keep.
I recommend BRS soda ash and calcium chloride: https://www.bulkreefsupply.com/1-gallon-mix-soda-ash-single-use-bulk-reef-supply.html
Pharma Calcium Chloride 1-Gallon Mix (Single Use)
Ultra-pure Calcium Chloride for 2-part dosing in your reef tank! Bulk Reef Supply 2-part additives are the perfect solution to replenish the intake of calcium and alkalinity coral consumes when it grows. Using only pharmaceutical based ingredients allows you to keep a cleaner reef with fewer...
www.bulkreefsupply.com
Miami Reef
10K Club Member
You don’t need to dose much initially. Try 1mL per day with an auto doser. Make sure you are dosing equal amounts but adjust dosages based on alkalinity, not calcium.
You don’t want to dose both products at the same time. I think 30 minutes apart works well. This is where the auto doser comes in.
Some people may say that your tank’s alk can be sustained for now via water changes. I do agree that it’s not mission critical yet. Your demand won’t start taking off until you add more corals and coralline algae starts to take off.
You don’t want to dose both products at the same time. I think 30 minutes apart works well. This is where the auto doser comes in.
Some people may say that your tank’s alk can be sustained for now via water changes. I do agree that it’s not mission critical yet. Your demand won’t start taking off until you add more corals and coralline algae starts to take off.
Danroo
Well-Known Member
i did the same thing doing water changes to bring alkalinity up, didn’t work. My calcium doesn’t drop every two weeks but my alkalinity drops .5 every other day. So I added baking soda in my top off water ( two tablespoons in a 5 gallon bucket ) manually add 1 cup every other day to keep the levels around 8.6
