Some questions about Alk dosing with the SA KHD

[Faithbleed]

Hi all

Im a new KHD user and have been working through setting up everything correctly.

Im keen to get the KHD take over my dosing and try to keep Alk stable.

I currently dose 77mL of Alk over the course of 5 hours (19:00hrs to 00:00) using a Ecotech Versa.

So I have a few questions:
- What would be the best way to spread out the dosing on the GHL doser over a similar time frame (in order to do a clean change over for starters)?
- I want the KHD to control that dosing period and try maintain my nominal dKH, how do I go about that?
- I was always told not to dose calc and/or mag at the same time as alk, so do I need to work around this if I were to switch to a 24 hr schedule?

Thanks!

 

[Ditto]

You could set it up to do the same period of time, you could do 5 time intervals, 19:00, 20:00, 21:00, 22:00, 23:00, I assume your other two(Calc and mag) are dosed at 15 minute intervals after alk? How are you doing it today?

Each Dose would dose 15.4 ml on the doser taking over Alk dosing.

What is your Alk swing per day at 77ml if you were not dosing? Your Alk would drop how much?

 

[Faithbleed]

You could set it up to do the same period of time, you could do 5 time intervals, 19:00, 20:00, 21:00, 22:00, 23:00, I assume your other two(Calc and mag) are dosed at 15 minute intervals after alk? How are you doing it today?

Each Dose would dose 15.4 ml on the doser taking over Alk dosing.

What is your Alk swing per day at 77ml if you were not dosing? Your Alk would drop how much?

Thanks for the reply.

What speed would you suggest I put the Alk doser on?

Current schedule on Mobius with the 4x Versa's is:
Carbon: 12:00 - 13:00 (1mL)
Calcium: 13:00 - 18:00 (15mL)
Magnesium: 05:00 - 11:00 (4mL)
Alkalinity: 19:00 - 00:00 (77mL)

Im not sure how much it would drop without dosing, the prospect of testing that worries me.

For what it's worth Im using RHF's Soda Ash recipe for my Alk.

 

[Ditto]

Slow is around 5ml a minute so to dose 15.4 is 3 minutes which is what I would do.

Do you know how much RHF soda ash to raise your alkalinity from 7.0 to 8.0?

 

[Faithbleed]

Slow is around 5ml a minute so to dose 15.4 is 3 minutes which is what I would do.

Do you know how much RHF soda ash to raise your alkalinity from 7.0 to 8.0?

Unfortunately not.

Is it a requirement?

 

[Ditto]

It makes it a bit easier, how big is your tank?

 

[Faithbleed]

425L SPS frag dominant with high growth. I add frags quite frequently so assume consumption wouldnt remain the same for long (its been increasing lately).

 

[Ditto]

Ok sorry for the delay had to read a little bit. Normally you would want to know how much it takes to rise 1 dkh but we will start this way and may need to adjust.

Have you decided which mode you want to do your KH control to be add on or adaptive

 

[Faithbleed]

Ok sorry for the delay had to read a little bit. Normally you would want to know how much it takes to rise 1 dkh but we will start this way and may need to adjust.

Have you decided which mode you want to do your KH control to be add on or adaptive

No worries, thanks for the continued advice.

I'll pause the dosing for a night and do 2 tests 24 hrs apart.

Most likely adaptive mode based on what I've learnt so far.

 

[Faithbleed]

Oky doke, so here's the results of the 24hr KH dosing pause:

Hannah Checker
02/08/2021 @ 6pm - 7.9 dKH
03/08/2021 @ 6pm - 7.2 dKH

KH Director
02/08/2021 @ 18:00hrs - 8.7 dKH
02/08/2021 @ 00:00hrs - 8.5 dKH
02/08/2021 @ 06:00hrs - 8.4 dKH
03/08/2021 @ 12:00hrs - 8.3 dKH
03/08/2021 @ 18:00hrs - 8.0 dKH

Seems like I currently consume around .7dKH in a 24hrs period.

 

[Ditto]

Ok let do adaptive mode and set them to 25 percent. May need to increase it but we can start there

 

[Faithbleed]

Cheers Ditto.

I've done 6 doses rather than 5 as it divides 78mL (my current dose) equally at 13mL per dose.

I've kept the control for the alk disabled, but is this what it should look like if enabled:

Does the "At deviation actual value to nominal value" amount mean that it won't make any changes unless the measured amount goes above or below 1 dKH of what the nominal amount (8dKH)?

 

[Ditto]

Glad to help.

No it makes small adjustments all the way up to the full 25 percent which is a 1 dkh based all on your nominal vaule. So for example let’s say it sees a .5 swimg it going to adjust your dose by 12.5 percent up or 1.6 ml for each dose until the next test. It not a lot the idea is small increments to your existing dosing to keep alk in check

 

[Faithbleed]

Glad to help.

No it makes small adjustments all the way up to the full 25 percent which is a 1 dkh based all on your nominal vaule. So for example let’s say it sees a .5 swimg it going to adjust your dose by 12.5 percent up or 1.6 ml for each dose until the next test. It not a lot the idea is small increments to your existing dosing to keep alk in check

Ok, thanks

So the KH ditector is now taking over Alk dosing, once Ive enabled adaptive, whats the next step?

Do most people switch over to 24hrs auto dosing or leave it the way im doing it (overnight)?

 

[Ditto]

Technically it adjust your existing dosing schedule not take over. Your still going to leave your dosing schedule and the KH Director will adjust it

 

[Faithbleed]

Technically it adjust your existing dosing schedule not take over. Your still going to leave your dosing schedule and the KH Director will adjust it

Ok that makes sense.

The doser does the dosing and kh director manages adjustments.

Whats the next step though? Leave it as is or switch to 24hr dosing?

 

[Ditto]

You could go to 24 but you should also dose cal and mag also on the same interval.