When to test buffered water

[Jhoussock]

I'm entering the world of buffered ro because I am relying on water changes to keep my ph stable and I'm not always going to be able to do frequent water changes (vacation etc.) tap ro mix is out due to high nitrates. My question today is after adding buffers ( seachem alkaline and acid buffer) when should I test my levels. (Kh ph) I ran an air stone in my holding tank all night and my ph is 7.3 after buffers and kh 2 usually 6.3-5.3 and kh 0 in a three day period I want a kh of around 4 and ph of around 6 I also don't want to get to those levels and do a water change only to find the ph drop or raise. So how long until the buffers are stable and take affect? Instant? 10 minutes? A day? I don't mind changing the levels quickly in my holding tank I just don't want to have drastic changes once the water is in my discus tank

[Second Hand Pat]

We generally recommend to not use buffers just because it can cause your ph to be unstable. May I ask why you feel the need to use buffers? Domestic discus are very tolerate of a wide range of ph and TDS values.
Pat

[RogueDiscus]

Pat, check out his previous thread in this section.

[Jhoussock]

I have a kh of zero and high nitrates in tap so I use 100% ro waterchange every three days with replenish for gh and discus trace added. My ph goes from 6.3 to 5.3 in that three days who knows what it would go down too if left alone for a week. My hope was to make my ph more stable but if it's not worth it I wont. I'm also worried my bacteria will eventually die off from the ph mostly in the 5.5 5.3 range

[RogueDiscus]

Considering your previous question regarding tds for grow outs, also, maybe some source of calcium carbonate would be an idea. Calcium for the grow outs, carbonates for the buffer. Just a thought, not sure of the best way to do that.

[Second Hand Pat]

Thanks, I did not have a chance to review your other thread. I see that replenish will increase GH and guessing discus trace does also (description does not say either way). Based on Seachem's description guessing you are using the alkaline and acid buffer to dial in your PH and KH. What happens if you only use the alkaline buffer?

I would approach this two ways; first in your aging container and second in your tank. I would add your buffer per directions then test ph/kh over several hours. I would think the water would stabilize over a 12 to 24 hour period. Do your water change and test the tank water over time to see how that changes. You may have to increase your ph/kh in the aging barrow to get some longevity over time in the tank.

To help stabilize the tank you could also add a little coral/limestone to the tank. You could also look at other product to see if it would raise your kh without doing the alkaline/acid buffer dance.
Pat

[Jhoussock]

I have a piece of coral a little bigger than a soda can, if I put this in the tank like a decoration will it help enough or should I used crushed stuff in my canister filter? Also if my water is staying in the 5.3 5.5 range will my bacteria eventually die off?

[DJW]

I use pure RO for the same reason. I agree with Pat, you certainly don't need the acid buffer, and there are other ways of adding enough alkalinity without using the Seachem alkaline buffer. The directions tell you to use both but that isn't needed in your case.

You can add minerals with replenish to the desired TDS. This is the GH. Discus Trace is also GH only. Then all you need is some KH, the carbonate alkalinity. How much KH you need depends on stocking level and how long till the next water change. If you are changing water every day, very little is needed, less than 1 degree KH. If you must for some reason go a whole week you will want KH of 3 or 4.

There are two methods. One is to find the amount of crushed coral or aragonite that keeps the pH stable. The idea is that the coral slowly dissolves as the pH goes down. This requires trial and error, and because calcium carbonate is barely soluble, you won't measure much in the way of KH because the coral is like a reservoir of KH that dissolves very slowly.

The other method, which I prefer, is to add baking soda at the same time as you add the minerals. You only add what you need because it will increase the pH a little too. If I know I'm changing water tomorrow I don't add any. One teaspoon of baking soda in 50 gallons raises the KH by about 1 degree. It will also raise the TDS about 20 ppm.

Because the replenish costs money, you don't want the TDS to be higher than necessary. I keep it between 30 and 60 ppm. To be on the safe side for fry development I would be tempted to keep the TDS around 180 ppm for the first 2 months.

I make my own minerals rather than buying the stuff, its cheaper. Once you get this figured out you can look at various recipes that are out there.

[DJW]

So how long until the buffers are stable and take affect? Instant? 10 minutes? A day?

I add minerals, discus trace, and sometimes a little baking soda to the barrels 5 minutes before changing water. I don't know about Replenish, but I suspect it would be dissolved within minutes.

[Jhoussock]

So I tried the baking soda 4 grams in 46 gallons and my kh is now 1 dkh but my ph shot up from 5.5 to 7 will this jump be less if I go up to 2 or 3 kh? Most people state a change of .2 in ph my jump was 1.5! Used a pen and API test and both said 7. Tds didn't change much I'm current at 98

[DJW]

You are mixing minerals and baking soda in the aging barrel, right? The ro first comes out with a low pH. Then you mix the minerals and age it. The aging brings the pH up. The only thing that matters is that the pH of the AGED water in the barrel is close to the tank when you do water changes. If the pH in the tank isn't falling (it has some buffer) the aged water and the tank should be close every time.

Do you have fish in the tank, or are you still cycling?

[Jhoussock]

Yes doing it in a barrel but no the aquarium water is usually down to a 5.3 by the time I water change and a 6.3 After a water change. It falls about 1 point in 3 days. Part of the reason I want to buffer. My plan is to do smaller changes every day with the buffered water. I understand the ph goes up when mineralized but I didn't think it would go up so much for just 1dk. My concern is if I take it to 3 or 4 my ph will be in the 8.5 range. Especially after seeing it go so high for just 1 dkh

[DJW]

Are you cycling, or are there fish in the tank? If you are cycling and no fish, the cycle will take forever at pH 5.3. Don't do this with fish in the tank, but if fishless cycling add baking soda to get the pH over 7, maybe 2 KH. The bacteria will love it.

At KH of 1 degree, a pH of 7.0 is to be expected. If you raise the KH to 2, I would expect the pH to go up to about 7.3

[Jhoussock]

The tank has 5 inch discus and rummy nose tetras. So am I ok to slowly change over the water say 20% per day. It isn't safe to go 5.5 to 7 in a water change right?

[DJW]

A drop from 6.3 to 5.5 over a few days is not a problem for the discus... the problem comes from the possibility that the lowered pH has stalled the biofilter, which would cause an accumulation of ammonia.

Before you change water you should test for ammonia.

The ammonia will be in its non-toxic form at the low pH, but when you change water the pH goes up and makes some of the ammonia toxic. If there is ammonia, add a dose of Prime (or two doses... depends on how much ammonia) and change 30 to 50% of the water. I would watch the ammonia and do another 50% water change tonight.

I'm very curious to know if the pH dropped down to 5.3 with the crushed coral in the system.

[Keith024]

Hey Guys,

So I am having the same issue I recently added seven(7) 4 to 6 inch Discus in my 350 litres (90 gal) tank and I am experiencing PH swings mainly downwards, I was using 100% RO water with PREIS Discus minerals and had a KH of zero and GH 5. PH was being kept at around 6,8 before it started going down 0,5 in a few hours. I then started adding some crushed coral to the sump and also mixed some Tap water (filtered through charcoal) and the issue seems to hopefully have stabilized a bit. PH is now at 6.6

I do a 30 to 40% WC every 3 to 4 days and I am now contemplating if to continue using 100% RO water with added minerals and Bicarbonate of Soda or a 50:50 RO Tap water mix. I just do not know what PH to expect with a 50:50 mix when the PH of RO water is at 6.5 and Tap Water is at PH8. I think I want to keep my discus in a stable PH between 6 to 7.

Anyone could tell me if there is a table online which can help me predict the PH of mixed waters? Or from experience please?

Thank you and happy Discus Keeping

PS yesterday two of my Discus spawned in the tank :))

[DJW]

Hey Guys,

So I am having the same issue I recently added seven(7) 4 to 6 inch Discus in my 350 litres (90 gal) tank and I am experiencing PH swings mainly downwards, I was using 100% RO water with PREIS Discus minerals and had a KH of zero and GH 5. PH was being kept at around 6,8 before it started going down 0,5 in a few hours. I then started adding some crushed coral to the sump and also mixed some Tap water (filtered through charcoal) and the issue seems to hopefully have stabilized a bit. PH is now at 6.6

I do a 30 to 40% WC every 3 to 4 days and I am now contemplating if to continue using 100% RO water with added minerals and Bicarbonate of Soda or a 50:50 RO Tap water mix. I just do not know what PH to expect with a 50:50 mix when the PH of RO water is at 6.5 and Tap Water is at PH8. I think I want to keep my discus in a stable PH between 6 to 7.

Anyone could tell me if there is a table online which can help me predict the PH of mixed waters? Or from experience please?

Thank you and happy Discus Keeping

PS yesterday two of my Discus spawned in the tank :))

Are you using RO because the tap water is high in nitrate? If thats the case, would a 50/50 mix have an acceptable amount of nitrate?

I think the best way is to increase the portion of tap water until the mix has enough KH to keep the pH stable from one water change to the next, and not be too concerned about having a particular pH.

The pH will go up as you increase the KH with more tap water.

Here is a graph showing the relationship between KH and pH, with the ambient CO2 held constant. The numbers won't match your tank necessarily, but the shape of the graph tells you how pH stability works.

105536

The biofilter is always depleting the KH. Suppose it takes 3 days for the KH to drop 2 degrees. If you start at KH=10 the pH will only fall 0.09 over those three days. But if the KH starts at 3 the pH drops by 0.47

I control the pH in my water with frequent WCs, but if you want to go 3 or 4 days between WCs the pH will have to be over 7... which is OK.

[Jack L]

Hey Guys,

So I am having the same issue I recently added seven(7) 4 to 6 inch Discus in my 350 litres (90 gal) tank and I am experiencing PH swings mainly downwards, I was using 100% RO water with PREIS Discus minerals and had a KH of zero and GH 5. PH was being kept at around 6,8 before it started going down 0,5 in a few hours. I then started adding some crushed coral to the sump and also mixed some Tap water (filtered through charcoal) and the issue seems to hopefully have stabilized a bit. PH is now at 6.6

I do a 30 to 40% WC every 3 to 4 days and I am now contemplating if to continue using 100% RO water with added minerals and Bicarbonate of Soda or a 50:50 RO Tap water mix. I just do not know what PH to expect with a 50:50 mix when the PH of RO water is at 6.5 and Tap Water is at PH8. I think I want to keep my discus in a stable PH between 6 to 7.

Anyone could tell me if there is a table online which can help me predict the PH of mixed waters? Or from experience please?

Thank you and happy Discus Keeping

PS yesterday two of my Discus spawned in the tank :))

this page
http://www.wetwebmedia.com/fwsubwebindex/fwh2oquality.htm

and the ro to tap formula was helpful to me.

[Keith024]

Thats very helpfull of you as usual DJW I will have a look at that in a bit. PH has now stabilised at between 6.6 to 6.8, I will try and keep it around 6.8 to 7 to have some KH for buffer.

Today the Melon eggs hatched and the parents are obviously aggressive, I wasnt planning to breed this pair for now but I guess nature takes its course. There is some stress in the tank and all the other tank mates have to resort to the other end of the tank and if not they will be dealt with aggressively by the parent melons. I also noticed that 2 of the other fish are today using only 1 gill. They dont seem to be breathing heavily at all and have also eaten today, just using one gill. Could this be due to them being harassed by the melons parents? :/

The system is not letting me attach pictures probably due to their size :(

[RogueDiscus]

Let us know if you continue to have trouble posting pictures. Someone here should be able to help you.

[Keith024]

The pictures seem to be too large to upload.

I think if I go for a 50/50 mix the nitrates will not be acceptable DJW. I am currently adding only approx 20 litres of Tap water to 100 litres of RO water for a water change. However I think I should go back to 100% RO and add some Bicarbonate of Soda and or Crushed Coral mix to the sump to keep PH at around 7. I have to decide...

[DJW]

Try resizing the pictures to get them less than 2 megabytes.

[Keith024]

105614

Ok managed to upload a pic I think. Unfortunately I had to remove the wrigglers as the parents were getting too aggressive to the other tank mates :/

[Keith024]

this page
http://www.wetwebmedia.com/fwsubwebindex/fwh2oquality.htm

and the RO to Tap formula was helpful to me.

Many thanks Jack L I am now reading your link and it is really informative :)