Photo period question

[Gary Majchrzak]

Looks good!
You're on the right track

 

[cardiffgiant]

Be sure to check your pH opposite of your peak photoperiod. I wouldn't be surprised if you are dropping below 8 at night. Especially if you aren't using kalk.

 

[magdelan]

So... if the PH is dropping below 8 at night, what affect is that having on my coral? What can I do to counteract it?

 

[Gravesj1s]

Nice Rodi pickup. Tank/rock looks pretty good.

dkh of 7 is borderline and might of been dropping between your weekly 90% water change.I once had an all softy 75 gal reef that would drop below 7dkh (s.g. 1.025) by day 3 of a 40% waterchange without supplementing .heavy coralline can suck up some buffer quickly
alk/dkh test is the one that is a must,imo/e.

In an established tank ,under normal circumstances Ive only seen 2 things bleach out corals like that ,high/low phosphate and unstable or low alk/kh. not talking fresh frags ,stings ,redbugs ect,here.
Just some thoughts

 

[Gravesj1s]

you mentioned battling algaes & cyano

tapwater adds high inorganic phosphate (form readily used by algae)
gfo binds only inorganic phosphate
fishfood into tank adds organic phosphate ( not readily used by algae) and not really harmful to corals even though theres lots of phosphate.Its also got a whole host of of things to deal with it ,primarily the skimmer ,much of it eaten ,passed around ,bound up ect.At the end gfo grabs whats been stripped to inorganic P.Gfo is not really effective for dealing with high inorganic phosphate

I still think the tapwater was atleast a part of the problem .not really a light issue.imo

 

[magdelan]

That's super helpful! Thank you. I wonder if my phosphates are too low. Maybe I'll begin doing only 50% water changes and see how that goes. I'll try adding the alk portion of the two part to try to increase that. My Ca was a touch high so adding the alk will give it some room to come down. We'll see....

Edit: just added some Alk and it precipitated out. Hmmm

 

[cardiffgiant]

What 2 part recipe are you using? Do you use kalkwasser?

Low ph or volatile ph is stressful to corals. If your ph is dropping too low at night you could try dosing kalk oppositite of your photoperiod to maintain some balance.

 

[magdelan]

Im using the Randy Holmes Farley two part recipe. I have pickling lime from Ball. If my memory serves me right, I could dump in the whole thing to a bucket of water and the water will disolve what it needs, yes? The rest will end up on the bottom of the bucket.

Also, dosing kalk opposite my photo period would require some sort of automate doser, no?

 

[cardiffgiant]

There is recipe 1, which uses baked baking soda (soda ash) which raises ph when dosed. And there is recipe two, which uses (un-cooked) baking soda mixed, which has a ph lowering effect. People that dose both 2 part and kalk are usually suggested to use recipe 2.

You can do kalk with an ato pump and a timer, a ato pump and controller, or you could use some kind of gravitational slow drip. I've never had experience with the latter.

 

[Gary Majchrzak]

for many years

for many years

I used to drip kalk in with a plastic gallon milk jug

 

[Gravesj1s]

Welcome. I know it was oversimplified and a sloppy post but typing on a phone sucks.

I wonder if my phosphates are too low

.

Maybe,but I doubt its the whole picture. Algaes &cyano can use phosphate quickly,given the impression of 0ppm. But, if it truly was 0 ppm you would not have any algae.Downside of testkits is there not in realtime.
Some of these processes happen so fast theyre almost instantaneous Take ammonia for example.Once a tank cycles you really cant get a reading for ammonia or nitrite anymore but it must be there or we wouldn't have any nitrate further down the chain.

Confession. I was never a big fan of test kits either and ive never tested for phosphate. I just used a visual approach.Got algaes ,got phosphate.