pH Mystery

Hi all,

I have a weird problem with my pH. I'm not testing for hardness since I live in Woodstock, Cape Town and it should be soft.

Three weeks ago I got a reading around 7.2 in my aquarium. On Sunday I tested it and got a reading of 8.

In the aquarium I have bogwood, plants and river sand (which comes from my previous 60l, which had a pH of 7.2 constantly). Any idea what is causing the increase in pH.

Odd thing is: the pH of my tap water is around 7.2.

I have been using a combination of spring and tap water in my water changes to lower the pH (spring water has TDS = +-150 and pH of 4.1!). I mix the two so I get a pH around 6.0 - 6.5 and then do a 10% water change. Right now the pH is sitting around 7.5 and I plan on bringing it down to 6.8 - 7 over the next week or two.

The fish seem content (I have rummy noses which still have their bright red noses and apistogrammas with bright colours) although the plants seem to be struggling a little bit. I have started dosing with excel and a few of the plants are beginning to improve.

Any ideas / suggestions?

 

Hi, not sure what causes it but there has been talk at a few LFS where I have been that in general our water ph has risen a fair bit over the last month or so. I have noticed it as well in my tanks, altho for now its sitting at 7.4 and has stabilized at that. I am not going to fiddle with the ph for now unless it rises again to 8 (had that reading 2 weeks ago, last week it was back at 7.4, mine used to be 7.2 as well). But the LFS have noticed with the tests that they do for clients that the ph has risen in some cases rather drastically depending on where they stay.

 

Fred:

What material is in your filter?
Are you adding any CO2?

 

Have you tested your KH? If your KH is as low as mine is out the tap your ph could be swinging all over the place.

 

Verndog: I haven't tested my KH but will do asap. Would a low KH value cause an upward swing though? I thought its generally a downward drop rather than upward swing from what I've read. Although I'll admit I have a lot more to learn about water chemistry.

Zoom: Sump contains: Filter floss, bio balls, ceramic rings, activated carbon and a refugium with some hornwort. No CO2 injection.

Wyvren: The pH out the tap is much lower than the tank water (tested on Monday) but I did two 20% water changes over the past two weeks which could've raised the pH. I did'nt test the water before putting it in the aquarium so it could be the case that the water going in just had a much higher pH than normal.

 

If your KH is to low the swings can be up and down. With a low kh mine fly's all over the place. Between 7-8. Remember, when the water comes out the tap it is full of Co2 wich will cause a lower PH. When the water gets a chance to get oxygen in the Ph will go up. Usually takes a day or two. This caused me allot of headaches before I learnt this : )

 

Thanks Vern! I'll keep that in mind and check the KH. I'll also start ageing the water rather than just dechloring and adding immediately. I've been trying to read up on the chemistry part but there is just so much to learn with all the different interactions.... Give me physics or maths rather!

 

Thanks guys, I'll set up a system to age the water over the weekend... Problem is my tank already takes up most of my flat so finding space for 80 litres of water may be a bit of a challenge

 

What are you measuring your pH with?

Drops, strips or pH meter and if pH meter, which type, a pen type or lab style meter?

Kind regards,

Dirk

 

Hi Dirk,

I went to my LPS to have the tap and tank water samples tested with a pen-type electronic tester. I use the SERA drop kits just to keep an eye out for any changes. I am in the market for an electronic tester. Would you be able to recommend one and direct me where to buy it? I have a budget around R1500.

On that note: I've planned my water ageing setup. My target is to get the water to a pH around 6.6 - 6.8 and very soft. I would like to eventually keep Discus once I can maintain the water quality. I'm going to take a 100l bin and place it on my balcony. The water will be heated in there while being aerated with a venturi system that I will attach to a spare uplift pump. Before being aerated it will pass through carbon and peat to filter out nasties and lower the pH. I'll just top it up after every weekly water change and keep it running permanently. Would this work?

 

Ok... I need to ask... WHY do you want to have a pH set at 6.6 to 6.8?
Are you planning on keeping fussy fish that require this level?

The common feeling on the forum is that a STEADY pH is far more important than the "correct" pH. Altering the pH all the time is very dangerous, and whilst you think you may be giving the fish the "optimum pH", you may find they will be more happy at a stable higher pH

 

Eventually yes. I would like to move onto Discus once I can maintain stable water quality although I will probably start up another tank for that venture. For the current tank I would like to put in some german blue rams once I have this problem sorted out.

I fully agree with your statement. Every time I fiddled with the pH (using chemicals) in my previous tanks I came up short. But at the same time I would like to learn how to be able to create AND maintain the right environment for any fish, fussy or not.

 

to soften ur water u should add ro water.. What substrate or rocks do u have in ur tank? Sorry if i missed this earlier..This could also contribute to hardening ur water.

 

I checked my kH for my aquarium: 7
pH is still 7.5

I set up a water production facility for my weekly water changes it seems to be working well: the water seemed to stabilise around 7.5 after 1.5 days from a reading of 6.5 straight from the tap (Thanks Verndog for that piece of wisdom!). I couldn't find non-treated peat so I've been using Seachem discus buffer to bring the pH down mildly - I tested this morning using the drop kits and pH is 7 (or just just below, test kit is not accurate enough) with a kH of 7. I'll test again this evening to see if it remains stable and have it tested electronically before putting it in my tank.

Thank you very much for the help so far and I'll keep you guys updated.