The real importance of water hardness...

[tjudy]

:?

How serious is everyone about water hardness parameters? I have mixed results whether I am anal retentive about hardness and pH or not. Does anyone use a 'hard and fast rule' on where they keep the hardness level for Pelvicachromis?

 

[Randall]

Water Hardness and Fry

Dear Ted,

Where water hardness and Pelvicachromis species are concerned, carbonate hardness, KH, from my experience plays a more important role with wild fish than it does with those that were tank raised in tap water.

Maintaining low(er) KH improves hatch rates because more eggs are successfully fertilized and develop properly. I don't think KH plays quite as important a role with tap water tank raised fish.

Thanks!

Randall Kohn

 

[Neil]

Agreed! However, hardness seems more important in some circumstances than others also. For example, I have always found that taeniatus are good candidates for shock-spawning. What I mean by this is that when you are trying to get that critical first spawn, it is helpful to somewhat drastically alter the circumstances. Going from most importers, etc. water for shipping to very mineral-deficient water immediately has worked very well for me. Many people acclimate fish slowly to various water extremes. With Pelvicachromis, I have had very positive results with putting them into pure RO. Additionally, when they are being stubborn, I do other manipulations as well. I have even taken a pair of P.t."Wouri" out of their tank, bagged them up, put them in a fish box and drove them around in my car for a day. They spawned shortly after placing them back into the tank with a large change of RO. I obviously would not recommend this proceedure for anyone else, but it shows, I think, that there can be numerous things at play in our fish breeding. I think some fish react to stresses differently, but shipping is stressful for all of them. Pelvicachromis seem to react well to an immediate improvement in their water. Softer water is probably an improvement. But there are other things that may be key as well, so hardness gets a moderately important vote from me.
Neil

 

[tjudy]

:lol:

Driving the fish around to get them to spawn reminds me of a theory we had a long time ago that if fish thought they were going to die they would hurry up and do their evolutionary duty!!!

:lol: :lol: :lol:

Thank you Randall and Neil. Both your points illustrate what I have seen, and hence the reason for starting the discussion. I have a wild pair of Pel. sp. aff pulcher form b that have no problems producing fry... lots of them... in dechlorinated tap. I have had other pairs of this form that required much softer water to get started. I have some tank raised Pel. sub. 'matadi' that only spawn if the water is mixed at least 50/50 tap/ro.

My basic 'rule' is 50/50. I go softer if I am not getting results. I also inject CO2 in all the tanks, so pH is at least 6.5.

Thanks!