How do you maintain stable PH in ULNS?

[xenon]

My system is SPS dominated and I run GFO/Crabon.

I cannot grow Cheato so what method can I use to maintain stable PH?

I was thinking about using my refugium as a frag tank and use a reverse light cycle. Would that work?

I was never a fan of dripping kalk to raise PH while using dosing pumps to maintain cal/alk/mag. It's just too complicated to maintain stable parameters.

 

[bobkill]

What's your pH run? I use bulk reef supply alk (soda ash) and I have it set up on rosin pumps and my alk is 8-9 pH 8.1-3 - I was understanding that it you dose alk on the reg pH will follow - I got yelled at on the chem foroums for 'chasing' a higher pH and was told to just to dose alk - hope that helps

 

[xenon]

Ok. Let's assume I dose alk with a dosing pump and dose every hour over a 24hr period.

That would buffer my PH but at night, the PH would still drop correct?

I could dose all my alk at night but would it not be better to spread the dosing every hour for 24hrs?

 

[rburns24]

I thought the same way as you do about dosing over 24 hours, but the reason you dose at night is dosing during the day can cause PH spikes. Dosing at night also helps to keep you night time PH stable. I use soda ash(which tends to raise PH) and dose it with my make-up water, but will soon be using a BRS doser to add it only when the lights are off. Hope this helps.

 

[MammothReefer]

I mostly ignore my ph. I just run my dosers (currently) 16 times a day. When ever I peak over @ my acjr it's always between 8.1-8.3 It's been like that for so long I stopped cleaning and calibrating the probe. I probably should though for good measure.

 

[Alex T.]

xenon, what are your ph fluctuations right now? When I was dosing vodka and MB7 my ph would run between 7.9 and 8.1 throughout the day with no ill affects. I know others that dipped lower that had incredible tanks as well. If nothing appears out of sorts, don't sweat it.

Also, with ULNS many argue that GFO could have negative results. GFO also aids in lowering ph as well.

 

[jnc914]

I run a CO2 scrubber much like bobkill. There are easy pretty easy to make. I fill an empty plastic Seachem container, holes drilled and black foam on the bottom, and fill it with Soda Lime. It is hooked up to my skimmer. Before the scrubber my PH was 7.9, now I am able to maintain it between 8.2-8.3 with ease. My alk typically 9.