Co2 in a low PH tank
hey guys I just had a quick question. I want to set up my new 46 gallon but the light that came with it is a high output light. I know I'll eventually want to get pressurized co2 but the question that I have is this: My PH out of the tap is 6.4 and all of my aquariums are running about the same .. I'm worried that if I put Co2 into my 46 that it'd drop the PH way too low .. An thoughts? The light is a coralife 2x39w high output both are 6500k bulbs .. This tank is destined (if possible) to be a dwarf rainbow/gourami tank with loaches or corydoras for bottom
I wouldn't worry about adding CO2 at the moment. There are a lot of fish keepers who do not use CO2. I personally don't and I have a well planted tank.
CO2 is only be needed if you had a very low fish load compared to the amount of plants.
Adding CO2 is adding another variable to your system that could go wrong. I think it is better to maintain a natural balance. Your fish should produce all the CO2 you need.
In the future if you needed to add CO2 for luster or if you found you were having problems growing plants, then that would be the time. Also if this did arise excel maybe a better option than pressurized CO2. It is a little easier to control how much you are adding. I have found money spent in a good light spectrum is much more important for plant keeping than additives.
I hope this helps,
That is going to be a very nice looking tank... I love that holey driftwood piece on the left.
Make sure you post pics along the way.
I second not fussing with diffused CO2. But to answer your initial question, yes, it will lower the pH. I note you are in the Portland, Oregon area; most areas of the Pacific Northwest and SE BC (where I live) have very soft water. The very low, near-zero KH means there is nothing to buffer pH, so it tends to lower naturally. Adding CO2 will obviously drive this faster. I've had tanks lower down below 5 naturally, with no added CO2.
You can check out the photos of my tanks under "Aquariums" tab below my name on the left. I rely totally on natural CO2 from the breakdown of organics in the substrate.
On your light, that is quite bright for these fish, so make sure you have a thick cover of floating plants. Water Sprite is ideal, and thrives in our soft water. And without an additional carbon source, the duration will have to be controlled to prevent algae from getting out of control.
Someone earlier mentioned Excel, a liquid carbon supplement. I do not recommend this, or similar products. They are composed of glutaraldehyde (and water), and this chemical is a toxic antiseptic used in hospitals to sterilize instruments, in anti-freeze, in embalming fluid, to clean ship ballasts and kill bacteria, etc. It is listed as dangerous to humans, will kill some plant species, and if overdosed will kill bacteria, fish and plants. Here's the material data safety sheet on API's product, which is near-identical to Excel:
Thanks for the info!
So after a little testing it turns out that the PH out of my tap is higher than 6. It's around 6.8-7.2 .. I did a little digging and it turns out the PH in the water quality report states it's 7.8-8.1 .. could the driftwood (which isn't producing any tannins) be lowering the ph by that much? I have yellow on the ph test on all of my tanks and they all have driftwood.
BTW Yes I'm going to be using floating plants to reduce the lighting and once 1 bulb burns out in the fixture I hope that it still works if I keep the bulb in it .. my t5NO fixture does and it's by the same company. I'd like to just use 1 bulb. I have the lights on for 8 hours. Will reduce to 6 if the algae pop's up.
Any way to tell what the approx KH is of our water byron? these water quality reports are like reading greek.. I'll hopefully be getting a test kit this weekend.
The driftwood can be releasing tannic acid without noticeably affecting the water color. What are you using to test the pH? I would suggest getting the API Freshwater Master Test kit along with the GH and KH liquid tests (also by API) in order to be able to monitor pretty much all you'd need to test for. You can add a calcareous rock to increase the GH and KH to keep the water chemistry more stable, and plants typically like harder water. There are also manufactured buffers that can be added if deemed necessary. I use pressurized CO2 myself, but that's because my tank needs it. As others have said, watch your plants to determine if CO2 is needed.
I am using the master test kit but I can't tell the difference between 6.4 and 6.8 on the PH because it all seems to be the same dang shade. I also have difficulty with 10-20ish on the nitrate because it is the same shade as well. I just have to take an educated guess. Our ground water in many rivers seems to be 7.4 on the PH and I was a light brown/yellow on the high range PH test so that's how I got my numbers.
I'll be getting a KH test this weekend. I don't mind having low PH. I just wanted to know, if in the future, I went with pressurized co2 if it would effect the ph even more. I realise that the driftwood would eventually stop buffering the PH and it would eventually go up but here in the NW we have super soft water and not much for buffering so I'm guessing my KH is very low as well. I was thinking of adding coral or oysters in some pantyhose and sticking it in the back of my aquarium so I can remove it when need be. I just hate thinking that I'm putting 7.4 water into my aquarium when it is 6 because of the driftwood. It doesn't take long for the PH swing to happen too. 24 hours later I test and it's 6 again. I usually do 25% water changes.. Pretty much vacume and I'm done.
the reason I revisited this thread was actually because I went through some of my first posts trying to see how far my tanks have progressed and I found a post where I said my PH was 7.4 in my old 10 gallon with no driftwood and I was like "Huh?" and I never thought to test my tap water I guess..
Oh - PS - I figured out my light fixture will run with just 1 bulb. So I'm just running 1x39w HO 6700k
yea i agree with op here, super low ph (6) shortly after w/c is a super low buffering capacity, so it wont take much to crash your ph. personally i wouldnt try to mess with it never had a good experience when trying to ad just ph gh and kh (all mu8st be played with to change water ph and keep it stable) as far as co2 goes you already know its going to lower the tank ph even further so your idea of bringing up the hardness is valid. just wanted to remind you, if you didnt already know gh and kh need to be brought up before you mess with your ph. the higher gh and kh will not allow the ph to swing drastically during w/c or when using co2. i think there is a member submited article about best ways to go about changing and maintaining ph. ill see if i can find
might be a good idea to pm byron with further questions since he was the one that did the interpretation from the books
I suspect your water board, like Vancouver's, is adding something to raise the pH, and in looking at the first page I found it. Sodium hydroxide, same as here. I have found that since Vancouver started this in 2001, the pH in my tanks does not lower as it used to.
Prior to 2001, our GH and KH were near-zero (less than 1 d as now) and the pH was well below 6. My tanks stayed there, but I added half a cup of dolomite in the canisters of my two large tanks to raise it to around 6.2. Then in 2001 with the addition of ash, the pH out of the tap rosed to 7 to 7.2. I removed the dolomite and now use nothing. The pH from week to week, with a 50% water change on all tanks, remains quite stable. It varies a bit from tank to tank due to volume, plants and fish load; 6.4 to 6.8 is the range. While I'd like to see this a bit lower for some of my tanks, I leave it alone. I know the GH is zero (except when I add Equilibrium to raise it to between 4 and 6 solely for the plants) and this is the real critical issue for soft water fish; the pH is less so, though you prefer it to be slightly acidic, and mine is.
Buffering of the pH and related issues was mentioned in the intervening posts, but I would not bother with this. As noted in the preceding paragraph, you are not likely to see any issues. Once the pH naturally lowers it will likely remain there. Stability is maintained with regular water changes, plants, and fish.
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