Cycling And Low Ph

[gumby]

Gday all. I'm in the process of cycling my tank with fish flakes. So far it is my 2nd week of cycling with the ammonia at 4. I haven't seen the nitrite spike yet, but patiently awaiting for it. My problem at the moment is that the ph is at a constant low. It has stayed at 6 for a long time. The ph of my tap water is 7.4. I did a 20% water change to attempt to increase the PH. I'll check on it tomorrow. Is the only way to raise the PH by doing water changes? I believe the low PH may be affecting some of my plants.

Currently I do have amazonia II, plants, and a DIY co2 if that helps any.

Many thanks in advanced.

 

[Miss Wiggle]

a low pH can definatley stall a cycle

firstly are you sure that the pH is 6, or is it just the lowest reading on your test kit? if it's the lowest on the test kit then it could actually be lower.

at a pH of 5.5 the bacteria we are growing will die off, another species of bacteria will grow in their place but these are much slower to grow.

you should try and raise your pH, big water changes will help.

I think it's the Co2 that's pushing your pH down so you may want to put something in to buffer it up a bit, something like a handful of crushed coral in your filter or something like that.

 

[pastabake]

I would ditch the CO2 until you've cycled. DIY versions are notoriously unstable. Especially as ideally you want the temp at 30C - so less oxygen already in the water ... so you really could do with aerating the water - as this also helps the bacteria - so CO2 at this stage isn't such a great idea.

 

[waterdrop]

The problem with Coral to raise pH during fishless cycling is that it makes its changes slowly. It can take at least a week before you see pH going up from it I've read. I've also been advised that you want to start with a rather small (maybe an inch round pile in your hand) amount in part of a filter basket. Baking Soda (1 teaspoon per 50G) will raise KH from 0 to 4 degrees german hardness, buffering your water without immediately raising pH, but allowing the water change to retain its higher pH. So the baking soda can work faster and is ok for fishless cycling, even though coral is a better thing to do in a stocked tank.

A problem with fish flake cycling and low pH is that the necessary water changes remove the ammonia and food and there is a time wait after the you recharge the new water with powdered flake before the heterotrophic bacteria can break it down to the needed ammonia.

I agree with everyone's comments - as the fishless chemistry itself drives the unbuffered water down past 6.2, the process slows dramatically and virtually stops at 6.0 and then as MW says, really bad things may happen at 5.5 and lower. Pastabake is so right that high oxygen encourages bacterial growth - higher temp and CO2 injection both lower it and I think the oxygen has the greater stimulus effect (imo.)

~~waterdrop~~

 

[gumby]

Wow great bit of information! Thanks all.

I'm fairly certain that the PH is at 6 mainly because the color matches spot on to the card.

I'll do another water change tonight, in hopes of raising the ph back up. I haven't checked the status since last night's pwc yet. Who would have thought that cycling would be such a hassle.

 

[Miss Wiggle]

it's a bit of a pain sometimes, but trust me, it's considerably less hassle than doing it with fish in!

 

[waterdrop]

it's a bit of a pain sometimes, but trust me, it's considerably less hassle than doing it with fish in!

...made me think of this:

Hassle of doing nothing:
Dead Fish

Hassles of both Fishless and Fish-In Cycling:
Lots of water chemistry tests.

Hassle of Fishless Cycling:
Holding your nose and adding drops/squirts/millilitres of ammonia to the tank.

Hassle of Fish-In Cycling:
Hauling out the Bucket/Python for daily (or more!) water changes to keep fish alive!

~~waterdrop~~

 

[gumby]

Tis true!

so far the ammonia seems to be at a steady 4 with 0 nitrites and 0 nitrates. PH still seems low, I didnt have enough time to do another water change last night. Looking to do a large, maybe a 50%, water change tonight.

 

[waterdrop]

When I was fishless cycling (well, I guess you could say I still am ) and I did large water changes to get the pH up, I always did either about a 75% change (75 or so being as low as I could go and not get air into the intake siphon of my cannister filter and I was just too lazy to shut it off) or else I would shut it off, close its intake/outlet valves and drain as low as I could go, which I called a 98% water change! After all, the only reason for 25%, 50% etc is mostly for fish themselves! The bacteria are happy just as long as you put their food (the ammonia) right back in and don't shock them too much with chlorine/temperature (the bounds of those shocks is highly disputed, but I like to treat them gently anyway since I've put so much work into them!)

~~waterdrop~~

 

[gumby]

Thank you waterdrop.

Would doing such a large water change shock the plants at all, considering that the water temps are the nearly the same.

 

[waterdrop]

..probably shouldn't answer this when in a hurry.. the plant specialists will find me in error, lol...

With plants I probably would at least leave enough water so that the water supports them and you don't have to replant from them falling over. They shouldn't mind the water change at all and will benefit from some fresh co2 in the new water. If you use a liquid fert. you will have to recharge the new water with an appropriate amount of that. You will dechlor and recharge the ammonia (well, the powered up fish flakes, right?) I think the plants will be fine with it.

Hopefully you'll achieve your goal of getting away from pH=6 and get it up there somewhere near your tap water pH. Then you need to watch pH daily and see if, or how fast, it drops back down to 6. If its too fast then you will have to consider testing your KH.

gotta run, later!
~~waterdrop~~

 

[backtotropical]

Hi Gumby,

The process the bacteria undertake to convert the ammonia creates an acidic by-product which will lower pH, so it will fall naturally in any cycling or cycled aquarium.

Water changes are a good way to raise the pH up again, but i have to agree with Pastabake that the CO2 is probably the main culprit here. CO2 will lower the pH of your water, which isn't really desireable when cycling, especially over and above the bacteria lowering pH too.

At a pH of around 6.0 the activity of the desired bacteria will almost cease, which will stall the cycle. At a pH of around 5.5, the desired bacteria will die off, as Miss Wiggle says, to make way for a different type of nitrifying bacteria.

I suggest that you should hold off on the CO2 injection until cycled, and do a big water change meantime to raise the pH. Hopefully that should fix your pH problem. If you are using fertiliser for your plants, you should stop that too for just now as light + ferts + no CO2 = algae. You can re-start the fertiliser after the cycle when you re-introduce the CO2.

With regard to your plants, the main things they will object to is large swings in temperature or hardness. Bear this in mind and you'll be fine. If you are roughly matching the temperature anyway, i don't foresee any problems whatsoever.

Good luck with your cycle. Keep asking questions.

Cheers

BTT

 

[gumby]

Thanks BTT and waterdrop. All very helpful info!

My ph prior to adding the co2 was already at 6, which is what confuses me the most. I'm told that the Amazonia II has been known to fiddle with the ph from time to time. So perhaps that is what started the drop in the first place?

Luckily I'm not in too much of a rush to add fish and shrimp into the tank. I'm fairly content with just plants at the moment. I wouldn't mind my plants establishing themselves a bit more before I add the fish/shrimp. In the meantime I may leave the co2, and just do frequent water changes until they are established. Some of the plants took quite a beating after their bleach dip, and I want to nurse them back to health before I remove the co2, and start the cycle from scratch again.

How does that sound?

 

[backtotropical]

Hi Gumby,

I think i've found the answer. ADA Amazonia will reduce the pH of your water. After a bit of reading, i found that it claims to lower the ph to between 5.5 - 6.0 which is best for most aquatic plants.

You don't need to start cycling from scratch, just keep up the water changes (although that kind of defeats the purpose of the Amazonia). The bottom line is that you need to do something to keep the pH up or your filter won't cycle at all.

Cycling needs aside, Amazonia gets a great write up as a plant substrate. I might try it myself.

I would be tempted to still remove the CO2 until the cycle is complete as it will only add to your pH worries. Then just keep water changing to keep the pH above say, 6.5.

Alternatively, and i wouldn't usually recommend this but your case appears somewhat unique because of the Amazonia, you could add Bicarbonate of soda to the water. This will harden the water making it difficult for the amazonia to reduce the pH.

Just some thoughts i strung together. Hope it helps.

Cheers

BTT

 

[gumby]

If that is the case, should I rely on a silent cycle? Just let my plants take care of the ammonia?