Nitrates or Ph to blame?

Terry Martin

Well-Known Member
BRS Member
This past January my tank took a turn for the worse. I made two interventions at the time, one on purpose and the other inadvertently. I was running a ultra-low nutrient system (nitrate .1; phosphates not measurable) and some people had suggested some nutrients would be better (I've got about 2/3 sps; 1/3 lps). I carbon dose (with Red Sea NOPOX) so I reduced the dosage. There was little effect so I continued lowering dosage then got pretty dramatic spikes up to nitrates of 5.0. Some SPS (acros) and LPS (Lobo, euphyllia) started declining. When I saw what was happening I started to increase dosage and reduce nitrates. In mean time, my two clams (including beautiful maxima) died.
At same time in January, I plumbed a 30g breeder frag tank into my system. I didn't think of this as intervention into chemistry. But the added turbulent surface area increased evaporation and rodi with kalkwasser in it went up about 15-20% and ph went up about .15. In winter my Ph usually peaks in 8.3-8.4 as my sump is in unheated basement. Now it peaked low 8.5s and regularly high 8.4s.
Everything is fine now. Tank has recovered. Nitrates are stable in 1-2 range and corals like that. Ph is down with summer to peaking 8.2-8.3.
My question for the experienced reefers here: was it the nitrates or the Ph? or a combination?
 
Your rodi unit may not capture all the chlorine and the kalk neutralizes it, just my guess


Sent from my iPhone using Tapatalk
 
I would double check the PH probe, most people included myself struggle trying to achieve a higher PH, yours been at 8.4/8.5 , seen a bit higher.
 
Honestly, I rarely check PH ever.
I'm more concerned about the big 3.
Alk, CA,Mg and the salinity.
I've heard that any carbon dosing can be a slippery slope.
I just do the 1-2 tea spoons of Kalk per gallon in the top off and leave it at that.
Water changes are more trustworthy than carbon dosing imo.
 
I would double check the PH probe, most people included myself struggle trying to achieve a higher PH, yours been at 8.4/8.5 , seen a bit higher.

Good idea, I did a salifert test now with my apex probe registering 8.04 and it looked under 8 so maybe it is registering a little high.
 
Anytime you get a questionable ph reading from a probe try to calibrate it and rule that out. Especially if it’s been a while since doing so.
 
I don't understand. Does that mean you think the high ph was my problem?

Not exactly, my guess is the left over chlorine in your RO caused the problem.
Bulkreefsupply had a video a while back showing chlorine/chloramine did not get removed by many rodi unit.


Sent from my iPhone using Tapatalk
 
When there is chlorine or chloramine in your water, it can lower pH.
The absolute pH value is not that important as long as it is in normal range.


Sent from my iPhone using Tapatalk
 
The increased turbulence and kalk removed the left over chlorine. I suggest get a chlorine/chloramine test kit to check your ro water to see if it is the isuue


Sent from my iPhone using Tapatalk
 
The increased turbulence and kalk removed the left over chlorine. I suggest get a chlorine/chloramine test kit to check your ro water to see if it is the isuue


Sent from my iPhone using Tapatalk

Thanks, I'll check and see if this is an issue.
 
Upcoming Events

April 21, 2024
Paul B
Club Meeting

Back
Top