Gh, Kh, Ph... Oh My Head!

[RobynR]

While waiting on my cycle, I'm trying to make heads or tails of all the other fun chemistry involved in fishkeeping and make sure my water parameters will wind up ok once the cycle is done.

My pH in the tank seems to stay pretty steady between 7 and 7.5 (closer to 7.5, I think), but it goes up a bit (still under 8) when I do a water change. My GH is 7 and my KH is 4. I'm having trouble translating all that into what I need to do to ensure that fish will be happy. I've read that I should lower my pH chemically, or that the best thing I can do is acclimate fish to whatever occurs naturally in my tank because it'll be more stable. I've also read that my water is too soft and the pH will fluctuate and stress or kill all of my fish. What should I believe?

I'm planning to keep South American fish -- corys, cardinals, a ram and some hatchets. Also working on acquiring some pieces of wood to decorate the tank, which I've heard may affect my pH.

I'd be grateful for any help getting this sorted out!

 

[Buddyboy67]

These fish actually like soft water but would prefer a pH of 6.8/7...try adding bogwood etc to the tank and the tannins it releases will help with this.Also chemical adjusters can be added to your tap water before topping up with water changes...

 

[mickspark81]

These fish actually like soft water but would prefer a pH of 6.8/7...try adding bogwood etc to the tank and the tannins it releases will help with this.Also chemical adjusters can be added to your tap water before topping up with water changes...

Bogwood is a great idea (i have a nice big piece myself) mine dropped my ph from 7.5 to 7

As for adding chemicals to your water to alter ph before water changes..Id strongly recommend against this

If you miss water changes in future (which will happen) or you get a mix wrong once (also good chance of happening) you risk a sudden fluctuation in ph which can be devastating to your fish

Most fish (Rams included) will be totally fine in ph 7 water as long as the water quality is maintained.

I was very very tempted myself to go the chemical route but after all the horror storys ive read about ppl making slight errors and losing their tank i decided against it and im very happy i did

 

[RobynR]

As far as the wood goes, does it have to be a specific type of wood or just any type of wood that releases tannins? And is there a point at which it loses its effect? I'd rather avoid chemicals if possible, because I just don't trust myself that much. My biggest worry is the fluctuation I seem to see right after a water change, when the pH seems a little higher. I've only done two water changes, just to get a feel for this sort of thing, since I'm still cycling.

 

[mickspark81]

As far as the wood goes, does it have to be a specific type of wood or just any type of wood that releases tannins? And is there a point at which it loses its effect? I'd rather avoid chemicals if possible, because I just don't trust myself that much. My biggest worry is the fluctuation I seem to see right after a water change, when the pH seems a little higher. I've only done two water changes, just to get a feel for this sort of thing, since I'm still cycling.

Unsure of the types of wood that release tannins other than bogwood/driftwood

Just because you have bogwood in your tank doest 100% mean lower ph. Sometimes the hardness of the water from ph buffers (pesky little things that fight against the ph altering effect)
worked great fo me great tho

Tannins in the water gradually over a long period would start to slowly decrease (time depends on how long the wood has already been soaked i suppose). However..this would be a slow decrease which would be detectable at each water change.

Your water will go like a tea stained colour also (which i happen to love as my tetra havnt ever looked soo colourful and it resembles the original water my fish come from)

Make sure you remove your carbon from your filter tho as it removes the tannins

You also mentioned your ph level is higher just after you do a partial water change. I had the same thing happen..You should let your treated tap water sit for 24 hours in a bucket then you should retest. When water is pressurised in your pipes it contains gasses which in my case higher the ph level by around 0.3. This returns to normal by the following day

 

[RobynR]

So in other words, I need a bigger bucket. I got a 5-gallon bucket that's just for the aquarium, but I think I'll want more like a 10-gallon if I need to let the water sit for 24 hours.

 

[mickspark81]

i wouldnt suggest a 10 gallon bucket lol as the weight will be too much (unless you planned on tipping some of that settled water into your 5 gallon bucket twice ;-)

I personally change 20 - 25 % water weekly. This in my experience can be done straight away without letting the water sit for 24 hours as the 0.3 or so difference will hardly be noticable with the other 75% of the tank water you have..

Any water changes of 50% or more may need more consideration tho

 

[waterdrop]

First of all let me say that with a water parameters of (GH=7,KH=4,pH7-7.8) and the fish you are getting, its not clear that you need to be putting special concern into this topic. Its entirely possible that you will be just fine.

I guess if the ram and/or the particular species of cory happened to be of particularly sensitive types then one could argue there might be an issue, but even with that there'd also be a good chance all would be fine I'd say.

To respond to the previous comment I'd agree that if you were planning on putting decorative wood in the tank then that's great and any slight effect it has on the water will be in the direction that's to the advantage of your plan. I disagree however with the idea of ever getting into the thing of altering water pH and hardness parameters by using bottled chemicals. I don't have time to go into the disadvantages but there are many long threads from over the years that cover it.

I am a believer in the principle that a good aquarist should be stubborn about budging away from the baseline hardness and pH parameters dictated by the house source water. It's ideal to build a stocking plan around those water parameters. However, even if the stocking is not apparently ideal for the water it still may be that if one is not interested in -breeding- the fish the water may still be perfectly fine as fish will survive and be ok in a wider range than they will spawn in. Remember, for fish, hardness changes are often used as seaonal timing signals that have evolved to maximize fry survival and so water parameters that are quoted to take advantage of this may have nothing to do with fish being comfortable for normal life.

If one *does* make the momentous decision to live with altered water, then the difficulties must be appreciated. The most common problem comes not in being able to alter the parameters but in forever after not having any "slipups" that allow the parameters to fall back to normal and in doing so, possibly kill the fish. What happens is you forget or are unable to successfully have a plan follow through during a vacation or something like that.

Now if one decides to take on the alterations anyway, then there is the job of finding out what method is most accepted for making the change. The usual feature of the accepted methods is that they are either slow enough not to let fish get hurt or that they do not let side effects build up. For moving hardness and pH upward the method of choice is to bag up small amounts of crushed coral (broken coral and shells sold at the LFS) in meshed bags and add them to a filter tray. The amount can be adjusted after you've had measurement feedback. Then the bags must be removed and cleaned to be maintained or the material will not be able to continue to slowly dissolve. For moving hardness and pH downward the method of choice is a dual combination of RO+tap fractioned water and at least one peat layer in one of the filters. This is a hugely more difficult proposition than crushed coral. The RO equipment is expensive to buy and to run. The peat is difficult because its a challange to find a source of the right type. Let me also note that while doing "both" is supposed to be ideal, its also pretty common not to do the peat aspect but to just do the RO+tap method by itself.

~~waterdrop~~

 

[RobynR]

If I did a 10-gallon bucket, I'd pour it into the 5 for getting it to the tank. Maybe I'll put one on my "to-buy" list just to have around in case I do need to do a larger water change, but glad to hear I can mostly get away with using water out of the tap.

Waterdrop, thanks yet again for all the detailed feedback! I think my water parameters tend toward what the fish I'm getting will want -- I think they mostly like soft and acidic, and although I'm slightly above neutral on pH, it's at least not really basic. I was just worried because on another board I received a comment that my water is too soft and will be subject to dramatic pH shifts unless I use some sort of chemical buffer. I don't want to do that unless I really have to, because I'm definitely the type who would slip up just once and have a disaster on my hands. Not planning on breeding, so just aiming for healthy fish.

For whatever it's worth, I took a tap water sample to my LFS and they tested it for me back when I first started up my tank. They said it looked fine and I wouldn't need to buy RO water from them. I figured if they're advising me against buying something, they must be telling me the truth. That was before I had my stocking plan finalized, but since my original plan was South American built around an angelfish, I don't imagine much has changed in terms of what my water should look like.

 

[drobbyb]

I agree 100% with waterdrop. Even fish as sensitive as rams can be acclimated to a higher pH (my brother has his in a tank with aragonite as a substrate) provided you do it slowly enough.

Your water is fine for South American fish. They prefer soft water, and you have that. My water is ridicously soft with a KH of 0 and a GH of 0 for comparison, so your's isn't that bad.