Need thoughts on adding sand to an established tank.

lpsouth1978 · Oct 6, 2019

I set up my system as a bare bottom tank a couple months back. This is the first time I have tried bare bottom, and I am regretting that choice, I like the look of it and it is certainly easier to keep clean, But I cannot keep the pH even remotely stable. I know not to chase ph, and I am noy looking to do so, but it drops SOOO dramatically in just a few hours that I am at whits end. I have my skimmer air intake run to outside, but it barely helps, if at all.

I am using baked baking soda to try and keep the pH up, I will raise it up to 8.0+ and within a few hours it will drop to 7.70 and will continue dropping If i don't add anything. Right now I have to add 3-4 tablespoons of baked baking soda everyday just to keep the pH in safe ranges for the fish. I moved the few corals I had into my other system until I can get this tank stable enough to put them back.

My thinking is that the lack of sand has caused there to be very little/no buffering capacity in my tank. Now I think I am going to add 150-200lbs of aragonite sand. Can I just rinse the sand VERY well and slowly add it to the tank? I know that no matter how well I rinse it, the tank will still cloud, but what can I do to minimize this? Also is there anything I should do to ensure the fish are safe and as happy as possible during the sand addition? any thing I am not thinking of or tips from those who have done this before are appreciated!

SPR1968 · Oct 6, 2019

I think I read a way of doing this is to get a long plastic tube, place the end of the tube so it’s on/near the bottom of the tank and then pour the sand down so that it reduces the clouding.

It might help turning any circulation pumps off while your doing this was well.

lpsouth1978 · Oct 6, 2019

SPR1968 said:
I think I read a way of doing this is to get a long plastic tube, place the end of the tube so it’s on/near the bottom of the tank and then pour the sand down so that it reduces the clouding.

It might help turning any circulation pumps off while your doing this was well.

Thanks, I could see using a 2" or 3" PVC pipe to make a "slide" for the sand.

SPR1968 · Oct 6, 2019

lpsouth1978 said:
Thanks, I could see using a 2" or 3" PVC pipe to make a "slide" for the sand.

Exactly yes and maybe a funnel to make it easier

Don’t ask me were I read this as I can’t remember but it sounds plausible. It’s funny what you remember! Lol

Bbfishb81 · Oct 6, 2019

If you don't add too much at a time, you should be ok. With my experience, I'd say a few pounds a week would be ok, just watch the parameters.

Sparkymarc · Oct 6, 2019

This is what I use. 1 1/2” pvc, 2”-1 1/2” reducer, and 4”-2” reducer. Cost $10-$20. Works really well. Rinsing most definitely helps

ZoWhat · Oct 6, 2019

DONT CHANGE YOUR BB!

Your BB removes a multitude of deadspots where uneaten food decomposes into NO3/PO4

pH is a stupid number to chase. Many many many posts verify this....

As long as your above 7.7, dont even give that pH number a second thought. Heck your pH probe might be giving you false number....or your pH test kit might be off. Both only give you a pH "idea" and NOT an exact number

So are you convincing yourself that you'll have more GROWTH with a higher pH?

BULLCRAP..... many of the "Tank of the Month" glamour tanks have pH in the 7.8s.

Dont go chasing pH numbers.

I only use my reading as a "distant early warning " to tell me if smthg chemically is wrong that I should investigate further.

.

AZMSGT · Oct 6, 2019

I’ve been considering adding sand to my BB. Not for any other reason other than the look of the BB just isn’t working for me. I was thinking of using something like posted above made out of PVC.

I‘m working on a PH solution that would control the in home CO2 rather than using more rock/sand. FWIW, my PH in Surprise, AZ runs 7.6-8.0 with nothing done to try to raise it other than opening windows in the morning... now that it’s cooler in the mornings.

Sparkymarc · Oct 6, 2019

I agree with skimjim. I’ve seen many beautiful tanks with 7.7 ph.

Sparkymarc · Oct 6, 2019

AZMSGT said:
I’ve been considering adding sand to my BB. Not for any other reason other than the look of the BB just isn’t working for me. I was thinking of using something like posted above made out of PVC.

I‘m working on a PH solution that would control the in home CO2 rather than using more rock/sand. FWIW, my PH in Surprise, AZ runs 7.6-8.0 with nothing done to try to raise it other than opening windows in the morning... now that it’s cooler in the mornings.

Cool weather is finally coming. We hit 100 last week here in NC! I know some people run an airline from outside to their skimmer to help with ph also

W1ngz · Oct 6, 2019

If reading the OP's top post diligently, it's stated that it will continue dropping below 7.7. This isn't chasing in my opinion, it's reacting to a problem. It's also mentioned that the skimmer line is already run outside. See below for a quote from the resident chemist here, but sand or crushed coral works to stabilize pH in freshwater tanks, because the pH is typically much lower than salt.

I've never run a barebottom tank, so I can't corroborate barebottom with low pH. Can anyone else?

What is the alkalinity in this tank?
The salinity?
What is the pH being tested with and is it corrobrated with something else?
What is the peak pH at lights out? Lights out should be the highest in the normal daily cycle.
Where does the pH bottom out if left alone?

Either the numbers are wrong, or you have such exceedingly high CO2 levels in the home that the skimmer isn't going to be able to make up for it. You might try sending everyone to the mall or something for a day, open every window and get some exhaust fans running to see if the pH moves. If it's in a closed room, shut the door and fully ventilate that room for 24 hours and see what the pH does.

I found the following on another site.

Code:

Randy Holmes-Farley
Reef Chemist

The sand in an aquarium does nothing for pH stability.
It does not dissolve except deep in the sand bed where the pH may drop below 7.5.
So the pH in a bare bottom tank will be no more likely to deviate from nominal values.

lpsouth1978 · Oct 6, 2019

W1ngz said:
If reading the OP's top post diligently, it's stated that it will continue dropping below 7.7. This isn't chasing in my opinion, it's reacting to a problem. It's also mentioned that the skimmer line is already run outside. See below for a quote from the resident chemist here, but sand or crushed coral works to stabilize pH in freshwater tanks, because the pH is typically much lower than salt.

I've never run a barebottom tank, so I can't corroborate barebottom with low pH. Can anyone else?

What is the alkalinity in this tank?
The salinity?
What is the pH being tested with and is it corrobrated with something else?
What is the peak pH at lights out? Lights out should be the highest in the normal daily cycle.
Where does the pH bottom out if left alone?

Either the numbers are wrong, or you have such exceedingly high CO2 levels in the home that the skimmer isn't going to be able to make up for it. You might try sending everyone to the mall or something for a day, open every window and get some exhaust fans running to see if the pH moves. If it's in a closed room, shut the door and fully ventilate that room for 24 hours and see what the pH does.

I found the following on another site.

Code:

Randy Holmes-Farley Reef Chemist The sand in an aquarium does nothing for pH stability. It does not dissolve except deep in the sand bed where the pH may drop below 7.5. So the pH in a bare bottom tank will be no more likely to deviate from nominal values.

What is the alkalinity in this tank? 9.0 - tested with Hanna DkH tester
The salinity? 1.026 - tested with Refractometer calibrated with 35ppt solution
What is the pH being tested with and is it corrobrated with something else? Seneye Reef monitor AND Pinpoint pH monitor (calibrated with 7 and 10 pH calibration fluid
What is the peak pH at lights out? Lights out should be the highest in the normal daily cycle. The seneye shows that it got as high 7.9 last night (I dosed baked baking soda before bed though)
Where does the pH bottom out if left alone? I have seen it go as low as 7.6 before dosing to bring it back up, I don't know how low it would have gone if left alone

I am the only one in the house and i doubt I create enough CO2 to cause pH that low, though I can open some windows in the evening (supposed to be in the mid 90's today, I am in the Phoenix area) and see if that helps.

Thank you for the info from Randy Holmes-Farley. It seems my thinking may have been off and I should reconsider adding sand (at least for the pH sake).

I just ran a litany of tests and it looks like my Ca and Mg are both quite low. I will work on raising those and see what happens to pH. My parameters are:

Temp - 77.6
SG - 1.026
pH - 7.78
Alk - 9.0
Ca - 260
Mg - 980
No3 - 20

W1ngz · Oct 6, 2019

Calcium can't be that low unless you have bad salt. Double check it before you do any dramatic adjustments. It may have been thrown out of balance a little by the baked baking soda, but not that much.

I'd re-run all these tests on a fresh bucket of salt that's been allowed to mix for 24 hours with some decent surface agitation to make sure the bucket CO2 is at equilibrium with the room.

The forecast is for more comfortable night time lows later this week down there. Try and get the windows open overnight a few days in a row and close them up before you leave for work for the day. That should clear out any CO2 questions.