help with dosing alk, speed at which PH drops

[schoolisbad1]

Without dosing, my tank drops to 7.8PH and rises to 8.2 when the lights are on. I'm using a api high range PH test kit for measuring which I don't think is super accurate. I have a dosing pump and dose 45ml recipe 1 BRS for alklinity. My lights run 2pm-10:30. I think the drop from 8.2 to 7.8 happens within 1.5 hours after lights out. My question is, should I dose every ____ small amount, the same amount throughout lights off, or dose a few larger amounts... for top off any water changes I use RO/DI water.

Any suggestions would be helpful! thankyou

 

[Randy Holmes-Farley]

I'm not sure what size tank this is, but if you already have the dosing pump, there's no reason to not dose in the late night to early AM just as folks do with limewater to boost night time pH.

 

[schoolisbad1]

ehhg. I was dosing a small amount every 1.5 hours, when I checked the PH in the morning it was too high...

 

[bertoni]

How high? Most often, tanks seem to come through limewater overdoses fairly well.

 

[Randy Holmes-Farley]

And how much was dosed? Do you have a skimmer?

 

[schoolisbad1]

I do have a skimmer, running all day. I also use a dehumidifier throughout the day and night in the room. . I was dosing 5ml every 1.5 hours, 10x over the night, 50ml daily. I checked my PH in the morning, it was about 30 minutes after it had dosed the 6th or 7th time, the PH was 8.8.
I've heard of people mixing soda ash alk (raising ph) with the non baked baking soda (lowers ph), mix, to level out PH does this work? Randy I know your genius with this stuff, have any suggestions?

 

[Randy Holmes-Farley]

I suspect your pH measurement may be in error.

When was the last time you callibrated it?

 

[bertoni]

Dosing supplement like baking soda and soda ash will have a temporary effect on pH. Baking soda can lower the pH a very tiny bit, and soda ash will raise it. They both need to be dosed as alkalinity supplements first of all, and then the pH effect can be considered.

 

[schoolisbad1]

So I was dosing BRS mix 1, which is soda ash, it raises PH. My lights are on from 2pm-11pm. During lights on my PH is 8.2 During the night my PH is 7.8. I need to dose 50ml per day to keep my ALK stable.

What I was wondering, is when I dose, is it a problem if the PH jumps up when I dose. Should I dose three or four times a night, or should I try and dose minimal amounts spread out many times?

Each time I dose, it the PH jumps to 8.8 or so, isn't that not good for the system? if I dose every 1.5 hours does the PH jump up, then drop down to 7.8, then jump back up to 8.8 on the next dose

I can't find any dosing pump setup information thats pretty much I need. I would like to know how often people dose for alk, and do they use soda ash or or baking soda. Can you make a mixture of the 2, to get an alk suppliment that just keeps the PH around 8.2-8.4?

If you guys don't understand what im talking about no problem. I feel like this thread is kind of worthless and I'm not getting my words out right

 

[bertoni]

There are lots of schemes for dosing. People use a wide variety of schedules. You could mix baking soda and soda ash, but in your situation, I would just dose twice a day, morning and night, and see whether the pH spikes were acceptable. pH swings are common in our tanks, and as long as the high and low points are acceptable, the tank likely will be fine. Keeping the pH in the range from 7.8 to 8.5 would be a reasonable goal to try to meet.

 

[schoolisbad1]

thankyou for your advice

thankyou for your advice

I mixed a 3/4 soda ash, 1/4 baking soda mix, might end up with half n half

 

[bertoni]

Okay, sounds like a good start!