Alk and pH

[bswe22]

I am not sure what to do. My alk has dropped down to 5.8 dkh and my pH is at 8.34. I have BRS 2 part for dosing (which I haven't used much yet, never really needed to). I do have the soda ash for alk. BRS's calculator says I need to add more than 3 oz's to get my alk up to 9. If I do that my pH will go through the roof! So when I tested yesterday my alk was at 6.1 dkh and my pH was at 8.2. I added, very slowly, 1/2 oz of BRS recipe #1 and it brought my pH up today but my alk has gone down. The corals I have are 2 birds nests, 2 acans, 1 wellsophyllia, 1 duncan, 2 small chalices and numerous snails. It really doesn't seem like that much when looking at it. Everything is small. So how do I get my alk back up while keeping my pH stable? I don't want this tank to crash! (scary)

 

Thanks

[J-Dog]

What are u using to test your alk? And what are u using to measure your pH? Your pH should not be that high if your alk is that low

[bswe22]

I am using the Salifert test kit for my alk and I have a pH probe (new and just calibrated) for the pH. I tested the "test solution" in the alk kit and it was right on.

[bswe22]

Ok, just double checked my pH with a Salifret test kit and an API test kit. Both confirmed the my pH is in the 8.3 range.

[J-Dog]

What did u use to calibrate your probe?

[bswe22]

Pinpoint calibration fluids. I did it with 4 and 7. I have 10 on the way. I had forgotten to order it when I ordered the probe, 4 and 7 was all I could get locally. I know it will not be as accurate with 4 and 7 but it is reading the same as the two test kits I have.

[MVPaquatics]

Use sodium bicarbonate. Aka baking soda. This will slightly lower pH. You can raise you alk a lot more without affecting pH so much by using a 3 part dose of baking soda and then dose one part soda ash. The pH drop will cancel the raising of the other

[J-Dog]

I just went through the same thing, and with the wrong calibration fluids, u are definitely getting the wrong pH readings. Once u get both the 7 and 10 calibration fluids and recalibrate, u will find that your pH readings will be a lot lower. I also tried using test kits to confirm my readings, but they are horribly inaccurate.

 

If I were u, I would follow BRS's recommendations on raising your alk. Use the amount they tell u to raise it 1.5 dhk/day, and eventually u will get to the number u want. You won't have any issues with pH, so don't worry about using baking soda (recipe 2) instead of soda ash (recipe 1).

[steelhead77]

IMO, you should stop dosing anything. For your size tank, the only thing you should be doing is a weekly 20% water change. This should keep any params well in the safe zone. When you start dosing you will get into the cycle you're in now. Test kits are notoriously inaccurate, a little too much or too little water (or reagent) in the vial and your readings can be wildly off. And then when you start dosing to inaccurate readings, bad things start to happen. Don't sweat it. With the corals you have, the demands that are placed on your system can easily be handled by water changes.

[PeteRock]

I agree with steelhead. You are making this too complicated. You don't need to dose that tank. Granted, these are may be good lessons to learn for the future, but the I think you are overcomplicating things with the bioload that you have. Steady w/c with quality salts should keep you good.

[MVPaquatics]

Water changes might help but at 20% a week isnt going to raise your alk enough. 3-4 points is a lot.

 

Do my ratio. I would feel comfortable doing it in one day. Raising the alk isnt the issue, especially going from low to normal, we arent going from normal to waaaay up (corals would notice that). The big deal is ph swing. At 5.8 dkh, you may be at 8.3 during the day but at night you are probably 7.7-7.8. Way too low.

 

I dont get why of something is out of whack, people say to test for it, and when its a weird reading, the blame the test kit, then why test? Its actually pretty simple chemistry. Soda ash raises alk, and ph. Baking soda raises dkh but can lower pH. Doing a proper ratio (about 3 or 4 parts baking soda to one part soda ash). I honestly believe you can go from 1 to 9 dkh in one day as long as ph is kept stable. Ask frankb, i helped him through thisa month or two ago

[frankb]

I totally agree with MVPaquatics. I've raised alkalinity from 5 to 10 dkh within a couple of days without affecting the ph. I've been using his formula and my alkalinity as been very consistent ever since.

[Smann]

Are you using baking soda right out of the box, I'd like to try this with my dosing only because i get less of the fine algae on my viewing panels when my Ph runs closer to 8-8.1 would like to get back to cleaning every 3-4 days instead 2-3

[Alterego]

Using a high quality salt, do a large water change, that should get your levels balanced again.

[Zwickm]

In most online posts I see where people with smaller aquariums are having trouble with parameters being off are those who are adding supplements. Less is more sometimes. I have a biocube 29 with an extra 10 gallons in a refugium and I do not dose anything other than ALK buffer in my top off water. I have done 5 gallon water changes weekly since it's cycle completed. It's a mixed SPS, LPS and soft corals tank. Have seen tremendous growth in the SPS within 3 weeks of being added. Parameters always stay consistent and in check. Again, I believe less dosing and consistent water changes are key in small aquariums.