PH creeping down, what to do?

[hmt321]

i have a 40 gal tank set up as a "native" north american tank here are my tank specs and fish list

Tank specs

40 gal
Heavily planted
Eheim 2227 wet dry canister (rated for 75gal)
No heater in use
60 lbs of pea gravel
1 watt per gallon for light
3 pieces of drift wood (2 are defiantly cedar, 1 is gum I think)

Fish list

5 sunfish (like SA cichlids) currently all under 1” they will get about 5-7” full grown

5 sailfin shiners (currently 1”- 1.25”) they get prob 2.5” max
1 madtom (a small native catfish, it gets to 2” max)

here are results from latest water test

ph 6.4-6.6
ammonia 0.0
nitrite 0.0
nitrate between 0 and 5 ppm

I feed this flake food, a pinch each morning
http://www.petdiscounters.com/product.php?productid=1093538&cat=948&page=1

I feed these floating pelets probably 2 times a week at night
hikari pelets

and i feed them a square of frozen bloodworms 2 times a week

I do weekly 25% water changes and a gravel wash

my question, my ph is creeping down. this tank has been set up for about 3 months all during the fishless cycle it held at a steady 7 ph, then it began to creep down

I added some crushed coral in a sock to the tank and the ph leveled out at 6.8-7 so everything was fine,
now the ph is creeping down again. i added more crushed coral but it does not seem to be adjusting back up.

does anyone know what is going on?

the only thing that i have done differently is scrub some green slime off of one of the pieces

any ideas?

 

[mooman]

What is the KH of your water out of the tap?
Kh in the tank?

After awhile the crushed coral in the bag will develop a bio-film (bacteria and whatnot) that will keep it from dissolving and buffering the water. Soaking it in a bleach/water solution and then rinsing really well (overdose with dechor also) will restore its buffering ability.

It doesn't sound like your overstocked or overfeeding. My guess is your tap water is just naturally very soft and poorly buffered.

 

[hmt321]

ill check the gh and kh and post it tommarrow,

I added a bunch of "new" coral to the sock but ill do the soaking thing. I wonder if by scrubbing the drift wood perhaps I messed up some sort of algae coat that allowed more tannic acid to seep into the water.

thanks for help

 

[Roan Art]

What is the KH of your water out of the tap?
Kh in the tank?

After awhile the crushed coral in the bag will develop a bio-film (bacteria and whatnot) that will keep it from dissolving and buffering the water. Soaking it in a bleach/water solution and then rinsing really well (overdose with dechor also) will restore its buffering ability.

It doesn't sound like your overstocked or overfeeding. My guess is your tap water is just naturally very soft and poorly buffered.

True, mooman, but the coral should also stablize the KH and prevent that from happening, no?

Wondering -- hmt321

Are you using any chemical pH adjusters?

We really need you to get a KH test as mooman advised. Test your tank water and your tap water.

Also, take some tap water and let it sit out overnight. Test it in the morning for pH and post it here.

Thanks!
Roan

 

[liv2padl]

the "sunfish" family contains more species of freshwater game fishes than any other in
North America, and includes not only black basses and crappies but also smaller
sunfishes such as bluegill and redear sunfish. thirty species are represented,
including native warmwater game fish.

typically, members of this family are nesting fishes. during spawning the
male scoops out a depression in the substrate in which one or more females
deposit eggs. after fertilization, the male guards the eggs and newly hatched
young, usually for several days. young fish feed on minute organisms at first, and later upon larger aquatic organisms. adults of the larger species, particularly the basses and crappies, eat mostly smaller fishes. rate of growth and sizes attained depend on the species and the amount of food available but most grow larger than the 5-7 inches you indicate.

a 40 gallon tank is FAR TOO SMALL to house even one of these fishes let alone 5 of them as well as 5 shiners and a madtom.

cedar and gum are loaded with resin and tannins which will certainly lower your pH, and will continue to do so for many months. while you 'may' counteract this chemistry by adding coral, i suspect that (a) your kH is quite low and (b) you haven't added nearly enough coral to mitigate the tannin effect.

 

[hmt321]

thanks for the post iv2padl

this tank is a grow out tank for the sunnies, i believe that they are longear sunfish, they were collected from the escatawba river in south mississippi about 2 months ago, I plan on keeping 2 or 3 for the long haul. I will let the others go in a small pond in my fathers back yard in a few months. sometimes it is tricky to train them to eat floating food and i wanted a few more incase some died. (I started with 7, one developed very unusual color patterns and the other some sort of parasite, and I culled them.) I kept some longears from 1998 to 2001 in a 150-200 gal tank that i salvaged from the dump, the biggest one got to 6" I know because the cat snagged it out of the tank and i measured it before the funeral. Needless to say i built a top after that.
The bedding action was pretty cool to watch, the fish would have its head streight up and it would swish its tail (using its whole body) to create a depression. i even had babies (none made it though) There was no room for the big tank in the house we live in now (my wife thinks a dinning room set is more important) unfortunatly the tank was broken a few years back.
The shiners and the madtoms will probably stay in the 40 but the sunnies will go on to a 100 or 125 gal tank at my office when my present lease expires in Oct. We treat handicap children and I believe that having a large "native" tank would be more educational and cheaper than cable tv for the loby. The idea or theme is to have a tank where all the fish are from local water (fresh water that is). I am thinking of 2-3 longear sunnies, maybe some killie fish (i think thats what they are, i catch them in my minnow trap all the time) a few shiners and perhaps a catfish, i dont want a bullhead they get to big even for a 125. The only local plant i have had any luck with in my aquariums is what we call "duck grass" it grows in the delta and i think it is native but i am unsure, if anyone knows of anyother native plants that grow well in the aquarium please send me a pm.
I agree that as adults these fish need much bigger space but i think that they are ok for the next few months.

The drift wood was picked up off the beach of lower mobile bay in south Alabama and i have no way of knowing how long it was in the water before i found it. I have used drift wood obtained in this manner for years but i will admit that before about a year ago i had no internet connection and I was not nearly as well informed as I am today about fish and there needs, water quality ect.

I was under the impression that ph problems caused by driftwood would have come about in the first few weeks after their introduction to the tank. the PH was consistant untill last week then the sudden drop off.

I dont use any "ph up" or any chemicals (other than the crushed coral) to regulate the ph.

I will post my gh and kh in the morning. thanks

 

[hmt321]

PH is creeping back up, I think that when i scrubed that piece of DW it allowed more tannic acid to seep into the water, i also added fresh crushed coral but it seems to be on its way up.

thanks for advise