PH too low for fry tank?

[James0816]

Need a quick answer as I'm in my last 24 hrs before hatching. I think I'm still rushing it but ready to go.

Just measured PH of the hatching/fry tank and it came in about 6.2. Hmmm....not liking it as I was hoping for bare minimum of 6.6.

Do you think that would be too low?

[MatsP]

I don't think it's too low as such. Of course, if it's that low, it may also be unstable - that may well cause a problem.

--
Mats

[James0816]

well...it is a freshly established tank. not worried so much for instability as i have that managed.

[Barbie]

Adding a couple small shells to release carbonate would effectively prevent a crash. Could you define newly established for me? ;)

Barbie

[James0816]

I've downsized my existing fry tank from a 10g to a 5g. Since I keep my pH normally at 7.4, it was recommened to lower the pH to get a better rate of survival for the fry. pH is naturally low from well water (<6). Was looking for a base number to start with on the new tank.

[Barbie]

What is your kH? Why would a lower pH increase survival rates for fry from anything but L183 or really softwater species? Hatching rate, yes, but fry themselves will be sensitive to pH crashing, IME. I also wouldn't recommend going to a 5 gallon tank for raising fry. Your success will be twice as likely in the larger tank. I personally don't recommend even 10 gallons for pleco fry. They just require too much food for the filtration to keep up with.

Barbie

[Borbi]

Hi Barbie,

..going slightly off-topic here, but:

Ancistrus sp. "L 107/184" is a clear exception to your rule, IME.
For me, the fry constantly need a low pH in at least their first month.
That even goes so far that during water changes, I (have to) add my alder cone extract (selfmade stuff) to the deionized water before dumping it into the tank.
If I add water first, and then add pH-adjusting stuff (alder cone extract, in this case), I always have some losses among the fry the next day.
After 4-6 weeks, it is then no problem to transfer them to my usual tap water.
With the procedure I established for me by now, I get survival rates of close to 100%. And while I did a lot of experiments with these little critters, the only decisive thing I could find was a low pH (which is closely linked to a bacteria deprived environment, of course). Even in a newly established tank without bacteria they die within hours..
These are, granted, by far the most sensitive Ancistrus fry I ever encountered.

Cheers, Sandor

[MatsP]

Sandor,

L107/L184 are also black-water species that naturally live in low pH water, unless I'm completely wrong.

Of course, we don't really know much about Oto fry, so it may be that they are sensitive to pH variations and need lower pH than the average Loricariidae. In general, I agree with Barbie - most fish are perfectly fine with hgiher/variable pH, including fry. Sudden variations are almost certainly worse than a stable high or low pH.

--
Mats

[James0816]

I haven't even been using a hatching/fry tank until just recently. I just let nature take it's course over in the main tank. Numbers stay pretty consistant at pH 7.4, KH7 and GH7. These were the average of several rounds of the latest testing. Steading moving backwards to some get the numbers where I had better success. But that's another story kept track in the Otocinclus Breeding journal.

As for the fry tank, this is uncharted territory for these guys. I have been increasing my testing variables to find out what works best for hatching and rearing the fry. Now granted that most species in the Loricariidae family are bigger than the Oto, I was hoping to get some good info from other breeders as to what they are doing and maybe adapt some of those practices for the Otocinclus. Taking many suggestions from other fish keepers. I've heard things from tank size, to water levels, pH, green water, etc.

So this latest round of testing involved a smaller fry tank with lower pH. And, as mentioned, my pH straight from the well is < 6. Great for blackwater but no so for other species. So after setting up this tank, the existing buffer allowed it to raise to ~ 6.2.

I moved over what I thought was (5) eggs and actually ended up with at least (9) moved over. Two went non-viable the next day (several other eggs in the main tank that were with this batch did so as well). As of yesterday, I counted (7) wigglers. Granted this is a very small test subject, but I believe I can safely say at this point, I got near 100% hatching which has never happened before.

My goal was to buffer to 6.6 but after these numbers, I may just stay put. Will greatly depend on how well the fry develop/survive.

It is soooo hard to test on such a sensitive subject but needs to be done.

[Farid]

hi guys,
the low ph thing about loosing eggs or fry is as far i'd guess only because acidic water is less suitable for bacterias...that's why for example you dont need to be scared that eggs of Paracheirodon axelrodi would get fungus...they are only ready when the water is really soft. i had mine at KH 0 conductivity at around 15ms a ph of 4.1! (still i got no eggs that time. but a breeder told me bacterias hace no chance in this water.

so to keep the cats in even soft water being worried about the pH...if you dont already have? add oxygen. it should let the ph rise a bit ...at least. if this will be a stable version? i dont know.

usually when my L200 keep eggs i leave the water as it is (as i got eggs right now) in 2-3 days if the male is used to the "inhanging tank" i make a huge waterchange in the maintank...with not soft water...no with tapwater...the conductivity is then around 240-260ms the ph will stay around 7,.. two weeks later i do the normal soft-water week...so the conductivity will be again 160-170ms...the fry will still be in the tank then. i had never problems. of course some fry always die (less with L134 od L397)

the L260 are more sensitivy if the step of the new added soft water would be too harsh...

farid

[apistomaster]

Almost all the most popular Loricaridae come from soft acid water.
I would personally be pleased if my tap water was naturally soft and acid. I hate having to wait for enough RO water to accumulate in my reservoir and would love to have it come out of the tap soft and acid.
A pH of 6.0 is not all that acidic so why would you want to change it? It seems like ideal pleco breeding water to me and perfectly suitable for raising the fry as well.
My almost standard conditions for breeding more challenging species is to have a KH >3 and a pH of 6.0 to 6.4.
I keep my Black Darter Tetras and Parotocinclus cf. epplyei in water with a pH of 3.5 to 4.0, KH>1, TDS 15 to 20 ppm. That is what I consider very soft and acid from a fish keeping perspective. I have been able to maintain this range in this tank without the use of any chemicals and by using only RO water. My RO water has always tested at a pH of about 5.8 for some reason. I don't use the mixed bed deionization resin media cartridge which came with my unit and perhaps it would make my RO water have a neutral pH of 7.0 if I did; I just don't know.
My impression is that water softness is more important than a given pH with regard to breeding and raising pleco fry but once most species are a month old they seem able to handle a 50% decrease or increase in TDS at any one time without any stress. Altering the pH is something I do more gradually. I allow very soft water to become more acidic by virtue of it's diminished buffering capacity or increase/decrease it by using more or less tap water in a RO/tap water mix.
All my water chemistry tuning is based on trying to avoid adding any buffers other than those already present in my tap water and mostly lowering the tap water TDS through RO dilution. Unless you are working with fish from naturally alkaline waters with high TDS it is rarely necessary to use alkaline buffers. More fish are lost through pH crashes caused by adding acid buffers than are caused by the more gradual natural acidification due to a low KH. The reverse is also true unless a gradual method such as using some dolomite/calcite in the filter system is used to raise the KH and pH.