Jump to content

Established Nano Tank pH keeps rising to 8.7


Recommended Posts

So this started when I bought a new house. I moved the tank from a bedroom which was my office to a formal dining room, which I closed off with doors. The weird part is that I didn't have high pH previously very often but in this new office, it's almost all the time. I can get it down briefly with a water change and seltzer add but by morning it's back to where it was. I do know that the protein skimmer helps aid in this, because aeration is the same thing I would do to my saltwater pool to get its pH to rise back to 7.4-7.6 if I add too much muriatic acid. How stable that is of course depends on my alkalinity. There is also another item to keep in mind, I have a pico tank about 10 from it in my butler panty next to my expresso machine and I do not see wild swings. I never dose over there and it remains around 7.8-7.9. The only thing that is different about the new nano setup is that its using CaribSea Life Shapes reef rock instead of the ArcReef base rock I used before.


I will state that there is minimal coraline algae in this tank since it was set up in July. My top off water is RODI and it tests close to 7.9 pH in the Trigger Systems ATO. The tank is being measured by a Neptune Trident and I also have Hanna items to test with amongst others. I will state that I am in this office for at least 8 hours typically most days, sometimes more and I don't have any plants in this area. I do have three GPU doing some mining in here and it does make it warmer than I'd like where I have to open doors regularly but I have not seen that affect the pH really. This is a Neptune Systems Apex EL controller BTW and the pico is using one I designed with Atlas Scientific equipment. Here's the parameters of the two (two numbers are provided for the nano 20g vs pico 3g)


Sal 1.024

Temp 79, 78F

Alk 9.3, 8.6

Ca 531, 410

Mg 1401, 1280


FYI I did a 5g water change with the Apex DOS on the nano yesterday. I have not done one on the pico since last week. The pico has a flat piece of well cured rock with a decent amount of coraline on it and supports my ricordeas and rhoadactis with GSP and dragons breath. The nano has two clowns and a damsel, along with some corals from my first build that I don't wish to lose (multi headed hammer, a torch, two acans, two trachys, two crabs, two snails. I have dosed pink algae from ArcReef as well as some copeopods from AlgeaBarn as well. I have All4Reef to dose if needed but it makes too large of swings in Alk if not careful and its 50/50 premix with RODI. Also, I have plenty of NoPOx and I did try dosing that for awhile but I felt it was causing the pH to rise when I did for any length of time.


 Could anyone help me as to why my pH will not stay in normal ranges?

Link to comment

Peak pH levels are usually dictated by photosynthetic demand for CO2 during the daytime.  


Alk levels will establish how high (or low) the range will be that the tank's pH will be in during these natural CO2 swings.


This photosynthetic effect would be magnified in a smaller tank...plus your new tank also carries a higher alkalinity for some reason compared with the old one.  (In fact, comparing mineral levels between the two tank, they appear to be quite different across the board.  Is this inconsistency on purpose?)


It seems like this post could be a case of too much technology and you're noticing something that isn't worth noticing...if everything in the tank seems happy.  (I didn't actually see a real problem mentioned.)

  • Like 1
Link to comment

Those measurements are not new tank to old. It's possible the Apex stores data that long but the old tank had different rock, different house but same set up of space and maybe more concentrated CO2 as this new house is 1000sqft larger. The two measurements are my current Nano and Pico tanks - 20g Red Sea Max Nano and 3g Fluval.


The corals in this tank are far more fragile to changes than the Pico which is strange (I mean air or a minor water change). The ph on it is typically 7.7-7.8. The soft corals seem to do great in that tank but the LPS and softies in the larger seem to be "not in the mood" for the higher pH. I moved a small Duncan from there to here and will try a few others that survived the move. I guess thanks for the tips but my question is why the whole pH point difference between two tanks that are maybe 10ft apart?


I know about chasing pH during swings, read Randy's post and Melev's posts too - I feel the pH and Alk stability is what's keeping my corals from taking off. According to the Trident, it's gone from the typical 9.2-9.5 I keep it at to being 10 or so with very minor All4Reef dosing. I haven't measured these swings with the Hanna as often as the Trident but is generally accurate enough in terms of trending up or down. I finally turned that down to 2ml as I know my five headed torch and others were using it before the move but closer to 5ml then.

Link to comment

ideal: cease testing for pH until there's a tank problem, and it'll take a marked issue to cause one and link it to pH


this process works so well, I'll never own a pH tester for nano reefing and no tank we set up by message will need one. For your reef to require pH testing in order to grow any coral would be astoundingly rare circumstances

the option exists to bench the kit and not run it, and enjoy the reef 100%. my current nano reef is seventeen years old, I've never tested it for anything other than salinity and temp.



Link to comment
5 hours ago, OfficeReefer said:

I guess thanks for the tips but my question is why the whole pH point difference between two tanks that are maybe 10ft apart?

pH isn't the only parameter that's significantly different between then two sides of your readings.  pH by itself doesn't mean or do much.  But temperature, alk, calcium and mg all being so different while each sample has the same specific gravity is something.  Can you test for ammonia?  Higher pH along and higher temperature are both factors that make free ammonia more toxic.


My theory from earlier is that the main difference is photosynthesis driving pH up during the day....and it's having a bigger impact on one tank than the other.  If you happen to test the water positive for ammonia, then that will be new info to your slow coral growth perception.  🙂


5 hours ago, OfficeReefer said:

I feel the pH and Alk stability is what's keeping my corals from taking off.

Two things.


One, isn't the Trident supposed to adjust your dosing automatically to maintain whatever level you set?   Why is alk moving?  (Ditto for other parameters.  Are they non-stable as well?)


Two, you did move the tank.  That can be almost like restarting, depending on the condition of the tank before you moved it.


Reefs are uber sedentary in the wild....corals get very adapted to their local flow and light situation.  


When you move a tank, it's exactly like a hurricane blowing through...every coral gets at least a slightly different flow and light situation.  So every moved coral undergoes stress (potentially a lot 😵 depending on the state of things for the coral before, during and after the move) and may even sustain internal or external damage that it has to recover from, and it has to re-adapt (if possible) to its new surroundings.


That's a lot...and for a coral it can definitely be a life threatening change.  For a real example, I remounted a birdsnest frag 180º backwards on its post accidentally after breaking it off during maintenance one time.   I glued it back onto the base where it snapped, so I know it was under "the same conditions" to my eyes, but the whole thing RTN'd over the next day or so.  


The only real difference for that birdsnest that I could tell was that since the coral was re-mounted "backwards" it would have been experiencing "the opposite" flow that it was adapted to....and that (apparently) was a mortal difference in this case.  (Birdsnests are known to be on the sensitive side....but this is sensitive.)

Link to comment

That is an interesting case. I had not thought about such slight movement but that's a good thing to know. I try to not move my corals where possible.


There may be a larger photosynthetic effect on the two. I'll continue to monitor them this week and see what comes of this.

  • Like 1
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recommended Discussions

  • Create New...