C02, Ph Shifts, And Other Fun Stuff

[The Other Dave]

Hey there, short time lurker, first time new topic starter.

Anywho, a while ago, I got an aquarium from a friend who was going to get rid of it. I've pretty much managed to keep it going (and looking a bit better), despite losing the few cherry barbs that were in there shortly after transporting.

Its a 12-gal Eclipse, as far as I know, substrated with (I believe) red sea florabase. Removed the stock filter-pads, and replaced with a cut fluval sponge-thingie, with two AquaClear BioMax media bags on top. The filter change took place over time (added the bags, left for a week or so, switched to sponge). Swapped the lighting in the hood for a plant/aqua bulb I was able to get at the hardware store (16w T8).

Other than that, the only contents of the tank are two pieces of driftwood, few hunks of hornwort, some kinda reddish crypt thats making a comeback, a small amazon sword, few plantlets of java fern, and two anubises: a larger one, and a coffeefolia. (I had removed a few non-aquatics, such as mondo grass).

So, about a week ago, I tried starting up DIY co2. Two 2ls, which run though a separator bottle/one way valve, into the tank, which bubbles into a collection 'cup' I made. So far, it has worked decent. Checking ph-kh has given me a 20ppm of c02, steady.

However, I used to have rock-steady ph7 water. Now, its pretty-steady 6.2. If I use sodium bicarbonate to raise the ph, it works, but any waterchange/ect means the ph drops fairly quickly back to 6.2 area. Its there any 'correct' way to properly buffer the change, or much I always check and correct with the bicarbonate?

Also, as a side question: I've recently grown 'cotton' around the co2 tube exit in the tank. From what I've seen on the forums, its a pretty standard happening, and nothing bad. I had added the separator bottle to stop this from happening, but it still seems to. If, perchance, I added water into the separator bottle, would it form there, and not in the tank? Or just happen there as well as the tank?

Thanks for any advice you might have!

The Other Dave
(Theres always more than one)

 

[wolfwolf]

What is your KH (Carbonate Hardness)? My understanding is that KH buffers any pH change. If KH is 0 the pH can swing wildly. I had to add some powder (can't think of the name, bought at LFS) to raise the KH in my tank. My pH was stable at 7.5 but dropped to 7.0. My KH had gone from 3 down to 1 before I got it back to 3. Now my pH is back to 7.5.

Co2 addition has an acidifying effect on the tank.

 

[The Other Dave]

Currently, my kh has been stable at approx 35.8ppm (2dkh?) according to an API test kit.

 

[Themuleous]

I tend not to be very keen on messing with the chemistry of the water by adding things. 2KH is fine even when adding CO2. My tank runs at around 1KH, which gives a very low pH but its never caused me any problems. Rather than having to keep messing with it, I would leave it be, 6.2pH is fine as well, so long as the fish are OK with that. I would say though to keep on top of the water changes, as KH does get depleted over time so you'll need the water changes to keep it topped up, but in reality that shouldn't require anything more than what you would normally do as part of maintaining the tank properly

Re the white fluff, yes half fill the separator with water so the CO2 from the yeast mix is released under the water and bubbles up through the water as this will 'clean' it. As you say that should then mean the white fluff grows in that and not the tank

I have to say the bell shaped diffusers dont work very well, have you thought about investing in a ladder or better get glass type diffuser?

Its nice to see someone doing a bit of research before posting

Sam

 

[The Other Dave]

Much thanks, Themuleous.

If its going to turn out that the tank just wants to stay at 6.2, far better to just accept that than fight it - esp. since I currently don't have any fish. Just have to make sure when that time comes, I look for ones who like that type of environs. Suppose it helps me a bit, as it pars down the stocking list without even having to think. Ah well, something to ponder another day, once I get the hang of keeping plants down pat.

As for the ladder/glass diffuser, I haven't had much time with the c02 yet, and just made do with what I had lying around the house. Made a pretty decent bell out of a grocery store freezer door suction cup sign holder, just cut the sign holder short and slitted a small 3oz cup into it. I do plan to get a glass diffuser as time goes on, but for right now, this seems to be looking half decent. Since the tank is also low/low-med light at this point with only the hornwort as a decent fast-grower, it should be fine (I think) for a little.

Added some water to the separator bottle - it seems to be working, but also seems to have drastically raised the force needed for c02 to build and enter the tank. Set that up last night, air mark is only half-way down the tank right now. Bubbles in the bottle steady as ever, and only has about 3/4" water covering the incoming airline. Perhaps one of the bottles just needs a recharge. I'll do that later on, and see what happens.

Thanks a bunch for the answers, any other advice would be greatly appreciated. Last thing I want to do is end up asking last weeks newbie questions all over again, heh.

 

[Themuleous]

All sounds good Dave

BTW just read the end of your first thread

The Other Dave
(There's always more than one)

That made me chuckle, its so true

Sam