Low PH!!

[Foz in Oz]

G'Day all,
I'm a new member, firstly its so good to find you guys helping one another out with related problems. I have just started keeping discus. I have 6 discus in a planted 240l tank (approx 200l water). I have a question you guys may be able to help me with. I am thinking of getting a co2 system for my set up. I have peat in the filter to keep my ph down but it seems to be going down to levels of 6ph and lower over the course of a week or two. I do regular water changes once a week. My additives are seachem prime, seachem flourish excel, a declourinator and no buffer. My lights are only on for 6.5hrs a day as I am trying to get rid of algie. My water temp is 28 degrees C, my ammonia levels are 0 my nitrite levels are 0mg but my nitrate levels are 20-30mg. When I do a 20% water change I don't add any buffers as the Sydney water is 7.4 and soft, this brings the ph level back up to 6.5 but then over the course of the week it goes down again. I thought the peat would of kept the ph at more of a constant level. Anyway I thought if I was to introduce a co2 system with a ph controller that this would help. I now know that its when the ph rises that the ph controller will switch the co2 on thus bringing the ph down. What does a co2 system do when the ph is already down. If the ph is already down to levels of 6ph and lower, how will this system work? also what % of aquarium salt do I need in my tank? any ideas, thanks Foz

[kalebjarrod]

hay foz welcome

the trick with your peat would be to use it in a storage container rather than in your canister, this way the water is brought down to your desired pH level before you add it to the tank water, it will then stay a little more stable in your tank

if your pH is already low your co2 unit won't work automatically.

if you are trying to get rid of algee, do a 5 day blackout and it will be gone :wink:

i normally only add salt when i am medicating, other regularly add it.

i think i answered your questions

[Foz in Oz]

Thanks Ryan very helpful hints. Now 1 question about black out for 5 days, won't my plant life suffer and possibly die?

[Bad Inferno]

Welcome Foz,

I live in Melb and the water has little to no kH. I have to use kh powder to increase the kh which inturn increases the pH so that I can dose CO2. Sounds tricky but when you get the (kh/ph=CO2) chart it falls into place.

My Melb water had zero buffer capacity and would change from 6.4 to 6.1 ph overnight (moderalty planted tank.

I had CO2 turned off for a while (burnt out solenoid) however since I have it back online I can really see the difference in plant growth and lower algea.

I run my system with 1 degree KH at 6.3 pH which equals a CO2 of 15 mg/l. On the low side of CO2 I know however I do not like adding too much kH powder to my tank and I can see the difference in plant growth and colour.

I got my ph controller for nothing thus I setup a system. However cost ver rewards of pressurised co2 is probably not worth it. Just stick some swords and val in the tank and admire the discus.

[kalebjarrod]

your plants will be morw than fine

they will actually appreciate it more because there won't be any algee to hinder there growth when your done

i just did my tank while i was away for christmas, worked a treat!

[Trebs]

Hi Foz,

I've been battling with soft Sydney water for a few years so your situation is very familiar to me.

Using CO2 in this way isn't really ideal as your Co2 will be switched off mor than it is on which won't help your plants much. There are easier ways to balance out your ph.

It's time to get yourself a kh test kit. If your water is anything like mine than the kh from the tap will be 3-4 and the kh in your tank will be about 1.

Until your ph is stable and your kh is at least 6degrees don't use CO2. I'd also advise against using CO2 with discus if you don't have prior experience with CO2. It is possible to achieve a very good planted tank without CO2 (it will also be easier to keep balanced). If you still want to use CO2 I'd advise trying it on a smaller tank to get some experience with it. plantedtank.net has some great info on using CO2.

As for the peat I wouldn't use it at all. The water straight out of the tap is already soft, using peat will only make it softer(reducing KH).

Ideally you want to get to a point where your ph is stable and close to what comes out of the tap. Once we know the kh we can look at ways of bring it up slightly. This needs to be done carefully as adding even 1-2KH can jump your ph up to 7.4 which can be quite dangerous. IMO the ph you should look to maintain in the long term is 7-7.3. Once we know your kh we can look at the best way to proceed.

[Aurora]

I use a powder called 'kH 7.0'

It raises the kH while setting the pH at 7.0, which is the same as what comes out of my tap. I raise it up to about 3-4 kH. Then even if I havent done a water change for 2 weeks the pH is still 7.0

Before this I tried the 'Sera kH Plus' liquid. It was very expensive and I had to use like half a bottle to get the kH to 4. Then I checked the pH and it jumped up from 6.0 to 9.0. So I think this powder is a much better way to go.

I have also seen the powder come in a 'kH 6.5' and a 'kH 7.5' versions.

Dave

[weird]

I would avoid buffers. Sounds like Auroras experience is different to mine.

I have found in my bare bottom tanks, ph is not a problem. But I do daily water changes, don't use buffers, age the water for 24 hours (with an airstone).

Foz, do you mind posting a pic of your tank it might help.

[Trebs]

Buffers work okay, until they are used up. Then your ph can go anywhere depending on where your kh is. Buffers also contain phosphates which means lots an lots of algae in a planted tank. Lastly they can be cost prohibitive. Buffers have there place in small tanks where it is harder to maintain conditions.

By understanding water chemistry there should be no need for buffers in a 4ft tank.

[bob]

i use ro/di water seachem discus 6.0 buffer and seachem neutral regulator works for me

[Foz in Oz]

Thank you for all your help guys, i am a lot wiser now!!! I will be checking my KH and will try to get this right first. I want to keep good plants and reduce the algea. I also want to avoid putting chemicals in the water so if that means doing more water changes then i m prepared to do that. There r a few mixed messages as i am sure always happens when you log a question on, but all are good. One thing thow I was always told that discus preffer a 6-6.5ph level, is this right or is that just for the wild variety?

[Trebs]

A lot of old literature will tell you 6-6.5 ph is best. This is not necessarily wrong but it doesn't tell the whole story. If you could keep your ph constant at that level I'd say great don't touch it.

IMO though it's better to keep your tank at a constant higher ph rather than a lower ph that is subject to fluctuations. This is because the amount of bacteria needed to break down ammonia and nitrite increases along with ph. This means if your ph drops and then comes back up the bacteria levels will need to catch up. This will lead to a mini-cycle in your tank. The amounts of ammonia and nitrite will come up during this period will depend on the size of the ph swing.

So basically at constant ph of 7-7.4(when the tank fully cycled at that ph) will be better than a lower ph that is unstable. If your tap water was higher than 7.4, say around 8 then this would be a problem but a ph around neutral will be fine.

[Foz in Oz]

thanks mate.

[kalebjarrod]

spot on trebs :wink: