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jsonnenmoser
Fri Jan 14, 2011, 11:04 PM
Hi to all from Melbourne

Back into Discus keeping after a few years of absense. Our tank has now been going for some 7 months and all Discus are doing well, fingers crossed, we haven't yet lost one fish! They are eating, colouring nicely and some of them even paired up and are spawning though we haven't had any fry yet.

Generally speaking, the Discus seem to be in good health and the tank seems to be doing o.k.

I used to test PH (as well as all other water parameters) with API and Seachem. Both only measure PH down to 6.0 which I thought was o.k. at the time as I had some peat in my Eheim.

About 3 months ago, I got myself a GHL with PH probe. ... o.k.. before I get flagged for this, the PH probe has been calibrated and recalibrated. It is in a GHL container between the outflow of the Eheim and the Aquarium. The cables of the probe do NOT cross any electrical wires and the distance between probe and computer is some 20 centimeters. The PH probe seems to be functioning fine. When I measure tap water, I get a +-7.0 reading, same with the test kits. When I measure our Malawi Tank, the probe shows 8.3, same as the test kits. In our Discus tank however, the GHL probe shows +-4.5, sometimes even going down to 4.2, which obviously the test kits can not confirm due to their range, they only show lowest value which is 6.0.

So now we are obviously a bit panicing and looking for the source of this low PH. Peat was removed from Eheim some weeks ago.

What is in the 400l tank:
10 Discus (medium size)
1 Cleaner Fish (some sort of Amazon catfish, name escaped my memory)
3 plants (Amazon swords)
1 Plant on root (I think it is drift wood, was bought like that from LFS)
Substrate is Flourite (approx. 3 bags)

Eheim Filter with Seachem Matrix and Eheim Pads and Eheim Coal Filter
Bubble Stone with Sponge Filter (in case we need to set up a quaranteen tank we would use this sponge filter for transfer)
Internal Blue Planet 36W UV Purifier with separate small pump

We never used Flourite as a substrate before and are suspecting that it could be the cause of the low PH? Previously we had Discus tanks, set up pretty much the same except with gravel as substrate and PH would be pretty stable at +-7.0 (tap water quality)

Water Values:

Amonnia 0
Nitrite 0
Nitrate 5-10ppm
GH 2
kh 3
Temp 28.3

We feed our Discus 1-2 times daily, only frozen Blood Worms and Brine Shrimps, 4-6 blocks in total per day. We do water changes at least every 2nd day, approx 60-80 ltr which equates to 20%.

After water changes (tapwater treated with Seachem Prime) PH tends to raise to +-5.2-5.5 and then drops again down to 4.x over a 10 hr period.
But it continues to drop, meaning, if we do not change water after 2 days, PH goes as low as 4.2 and would possible go even lower without a water change.

LFS recons it might be overfeeding and/or too much disolved waste. However, we do use a siphon gravel cleaner to clean the substrate on water change and there is hardly any "dust", meaning the water getting sucked out is pretty clean. There is also not too much food left, we take time feeding and usually wait for a food block to be consumed (picked up) before inserting the next block. So it is not a matter of "food everywhere"during/after feeding.

The only other "thing"in the aquarium, which we also never had before is a commercially available (bought with aquarium and installed by LFS) background. This is a "rubber/poly"type background which got siliconed in by LFS. No idea if this could cause a low PH? perhaps due to certain materials used, but then again, surely someone else would have noticed that before.These backgrounds (which are not cheap) are sold by all LFSs in the Melbourne area.

Any advice and experience would be greatly appreciated

best regards

Ina & Jurgen

ILLUSN
Sat Jan 15, 2011, 12:44 AM
4.2 is fine for discus my heckels lived best at 4.0

clean your filter replace your pads replace 1/3 of your media, a build up or organics in your filter or within the media is causing acidification of your water

BigDaddyAdo
Sat Jan 15, 2011, 09:19 AM
On a different note you are not giving them an adequate diet IMO. You should add a good pellet food in there. BW and BS are not enough.

How often do you clean out your filter?

Can you leave some tap water in a bucket overnight and test how the Ph changes over that time?

jsonnenmoser
Sat Jan 15, 2011, 10:36 PM
4.2 is fine for discus my heckels lived best at 4.0

clean your filter replace your pads replace 1/3 of your media, a build up or organics in your filter or within the media is causing acidification of your water

Hi ILLUSN,

that is certainly reassuring, I am sure it is more the discovery that our PH is that low which worried us.

In regard to filter cleaning, we do that regular 6-8 weeks intervals. However, we never yet replaced any media. Half the sponges/media get washed out in Aquarium water, the other half in tapwater (which should kill most bakteria?). This process we alternate with the next clean. The only sponge I have not cleaned for a while now is the "bubble filter sponge", that has been going for some 4 months or so, will get to that today.

thanks for the advice,

best regards

Ina & Jurgen

jsonnenmoser
Sat Jan 15, 2011, 10:48 PM
Hi BigDaddyAdo


On a different note you are not giving them an adequate diet IMO. You should add a good pellet food in there. BW and BS are not enough.


I do agree with you! Having that arguement with my wife ALL the time. As it is HER tank, she obviously (thinks) she's the boss :-) Bottom line is, I feed my Malawis a variety of dietry (dried and frozen, bits and flakes). But according to my wife, HER discus don't eat the dried stuff and beef heart is too messy (for her). I know it is not ideal, but hopefully she will relent one day and start feeding a better variety. Despite that, the discus seem to be doing well, we got them as juveniles some 5-6 months ago and they are all growing and "getting fat" which makes it more difficult to argue my point in regard to feeding variety.



How often do you clean out your filter?


see previous reply



Can you leave some tap water in a bucket overnight and test how the Ph changes over that time?

Will do that test, just a matter of taking out the probe and filling its gap in the GHL container, not necessarily an easy task, but I'll get around to do that, just to satisfy my curiosity.

cheers

Ina & Jurgen

ILLUSN
Sun Jan 16, 2011, 01:20 AM
ok you really need to repace the white fine sponges EVERY clean the corse sponges once every 3-6 months.

the problem with biomedia is the majority of the biomass grows within the media its self,as a result mulm builds up within the media and starts to decompose, as it does it causes the water to go acidic, if you notice very strong acidification replacing 1/3 removes all the material traped and stills allows 2/3's of your filter to re colonise the new stuff, my advise is next clean replace 1 3rd and check ph if it starts to drop again replace another (diffrent) 1/3 generally you'll get few years out of biomedia i use the old stuff to cycle new tanks.

BigDaddyAdo
Sun Jan 16, 2011, 01:21 AM
Maybe she will change her tune when they all get diseased and die. ;)

Why do you rinse in tap water?

I rinse the sponges from my canisters in tap water but i see no benefit from rinsing the rest of the media in anything other than tank water.