Stabilizing pH during w/c problem

[John M.]

I have a 75g AC - mostly Malawi - using 4" Seachem EcoComplete cichlid sand ( packaging says will keep pH @
8.3). My problem is when I do even a small w/c - 15-20% - pH goes from 8.3 to 8 - 8.1 then takes about 30+ hours to reach 8.3 again. I even add during w/c in a gallon jug of dechlorinated water with a mixture of 1.5 capfuls of Microlift pH 8.5 buffer, 2 tsp. of baking soda and 1tsp of cichlid rift lake salts. TDS is +260 and my tap water pH is about 7.4 and is moderately hard. I seem to be adding a lot of buffer but it doesn't appear to have any effect once added with the new water. Any Ideas? TIA

 

[Evz jardini]

Have you checked your GH and KH levels when testing your water ? Keeping these in check will keep your PH balanced and prevent the drop from happening

 

[viejafish]

Look like your tap water has high temporary hardness which will dissipate over time. If you don't know what is temporary hardness, here is a link to explain it.

https://www.corrosionpedia.com/definition/1071/temporary-hardness

I don't think there is any harm to your Malawian fish, which prefer hard water anyway. It's best to let your fish adjust to the water than to meddle the water parameters with chemicals.

 

[xraycer]

It's best to let your fish adjust to the water than to meddle the water parameters with chemicals.

Agree

 

[John M.]

Tested my tank & tap water tonight. Tank : KH - 270ppm = 15dh ; GH - 100ppm = 5.6dh ; Tap : KH - 40ppm = 2.2dh , GH - 100ppm = 5.6dh . pH of tap water after 24 hrs. = 7.3. Also here is a quote from Dr. Paul Loiselle when a person asked him on his forum if there was a problem with his pH fluctuating when doing 'frequent partial W/C's' , his tap pH was ~ 7.4 and he was using crushed coral substrate which would start pushing the pH towards 8 after the W/C.
"What is far more critical to successful husbandry of rift lake cichlid fish is proper nitrogen cycle management. These cichlid fish are extremely intolerant of ammonia and nitrite. The program of regular partial water changes you presently practice may depress the pH in your aquarium somewhat, but its contribution to the well being of your fish far exceeds any imaginable benefits from a higher pH. Your management practices are exactly those I would recommend to a prospective rift lake cichlid fish aquarist. Just keep up the good work and don't lose any sleep over those pH values."

 

[John M.]

Forgot to mention those tap water levels of hardness are low and yet the tech who services my home furnace says I must have really hard water because the humidifier filter gets caked up with mineral deposits really fast.

 

[HarleyK]

How about you pre-condition tap water in a barrel to the desired parameters, and them conduct the water change with that water?

 

[John M.]

How about you pre-condition tap water in a barrel to the desired parameters, and them conduct the water change with that water?

Thanks for the advice, seriously considered doing that but logistically would be very difficult, especially now that I'm doing 15% W/C 's every 3-4 days to keep the nitrates down.

 

[John M.]

Did a 50% w/c Friday eve. due to high nitrates - ~40ppm - pH b4 w/c = 8.21 ; added a ton of pH buffer 8.5 product - powder (3x rec. dosage), some epsom salt and 3x dosage of rift lake salts in solution and added to new water being added. Within 1hr. of w/c pH was down to 7.9 and in 2hrs. 7.86 - bottomed out there. Today @ 6pm pH is 8. Don't understand why this happens when adding 3x the buffer needed. Nitrates are below 20ppm and fish appear to be ok. Also tested my tap water - dechlorinated - for nitrates = 0ppm.

 

[John M.]

Finally able to get a "somewhat" stable pH after w/c. Bought a Malawi/Victoria buffer product that says it will keep pH between 7.8 - 8.2., when adding 1 tsp./10-20g. A few days ago did a 15% pwc and added 2.5 tsp. of buffer. pH b4 w/c ~ 8.10, 6hrs. after it bottomed out at 7.87. Within 30 hrs. pH back up to 8.11 so it seems buffer helped in reducing ph drop from .4 to only about .2 difference. Fish look healthy & eating well. My male P. socolofi has paired off with a female and building a 'nest' but no fry yet, so I assume the minor fluctuation in pH has bothered them.