Fowlr ph

[nothingfishy]

Hey guys,

I have a 150 fish only tanked stacked pretty high bio load wise. I have a sro3000 skimmer, filter sock, uv light, and just stared running bio pellets.

I do weekly 15 percent water changes, with RO using instant ocean. I threw my ph monitor on it for a few days, and observe it at various times throughout the day. Before lights come on, during the day, right before lights shut off, and a few hours after lights are off.

I never see any ph swing of any type, it is almost always locked at a low 7.8. The only time it budges, is right after feeding, when it drops 2-3 hundreds.

I was told that sounds problematic, that I should be seeing a swing, even if only a tenth or. Is it possible, that being my tank is fish only, with relatively weak lighting, that I do not have any photosynthesis going on?

With the exception of a few algae spots on the rocks, I generally do not have any algae, and can get away with magnet cleaning glass once every 3 weeks or so.

Thanks

 

[Randy Holmes-Farley]

pH 7.8 is generally OK. It is at the low end, but many folks have pH that low. Lower worries me as aragonite may begin to slowly dissolve.

 

[sc50964]

What's your reason for keeping it so low?

 

[Randy Holmes-Farley]

It isn't his intention, just the observed pH.

 

[sc50964]

I had fish getting sick a couple times and the PH was low. After that, I have always kept the ph up around 8.2 to 8.3 and also make sure KH isn't too high.

 

[nothingfishy]

Yes randy is right, it is not my intention, just what it happens to be. Keep in mind to, it was 7.8 yesterday right after a 50 gallon water change (to remove proazi). So 33 percent new water, 1000 gph return pumps, (after head pressure, before they are 1400), and also a vortech mp 40. So flow and oxygen I don't believe are the issues. I can buffer it, but my alk is aready a 9, so that would just throw that up higher.

So randy, knowing what I have going on, is there anything you would suggest, being it is in the low end, and being it is fish only, zero inverts etc.?

 

[nothingfishy]

Also, did I hear correctly, that every tank should have a swing between day and night? Could it be there is just not enough photosynthesis ongoing to see a swing? Like I mentioned, I cant visably see any algae, but I know that doesn't mean I don't have it.

 

[Randy Holmes-Farley]

Every tank will have a day night pH shift if there is significant photosynthesis going on. If it is a FO, it may not have enough to notice.

I personally wouldn't worry much about pH in a FOWLR. I'd just supplement alkalinity when needed with a high pH additive (like a two part that uses sodium carbonate), and beyond that, live with whatever it was.