Switching salt?

[salty_dog]

I have a tiny 3g tank with LPS and a montipora cap. Starting to get small spots of coralline growth. The montipora is growing pretty well.
Using Instant Ocean with RO water. Alk is 8 after mixing. In my tank alk will drop to as low as 6dkh 4-5 days following a water change. I try to water change 1 gallon 1-2 x a week , which gives me 7dkh after the change, occasionally 8 if I do a bigger change. Just can't always get that 2nd water change in.

Should I switch to higher alkalinity salt now that the tank is coming along? If so, how do you introduce a new salt?
I don't have the ability to check calcium, magnesium right now.

Thank you!

 

[JohnK]

I have always found IO to be perfectly adequate. Alk usually more like 8-10 with fresh made IO at 1.026 SG.

To clarify, are you seeing the alk drop gradually between water changes, or drop fairly quickly after doing a water change? (it sounds like the latter, just checking)

If it is dropping after doing water changes (?), I'm wondering if you may have some SG test error? I say that because if your SG is a bit lower than your test method is saying, then that would explain the alk being lower, and thus bringing the alk down after a water change. Your seeing a consistent alk of 8 with IO suggests it may be a bit low in SG.

*Also note that if you happen to be using a hanna alk checker, the reagent tends to drift into misleading readings if you have the bottle open for a while. I stop trusting mine after 2 months or so (keeping the reagent in the refrigerator)

 

[JohnK]

Sorry if I was answering the wrong question.

If you are using water changes to replace consumption then yes, you could change to another salt with higher alk to maintain that at the current rate. The problem is if you are seeing specks of coralline now, it’s taking off and that consumption is probably going to increase steadily as your tank grows.

For the short term going to something like reef crystals will work. Longer term, you’re going to want to start reading up on using 2 part, kalk, allforreef, or another “balanced” additive or system.

 

[dz6t]

Since you are using IO salt, switch to Reefcrystals can be a good way to go. Alkalinity of purple bucket IO salt is not consistent, I have seen alk from 7 to 12 dkh from batch to batch. Reefcrystals is a lot more consistent.

 

[JohnK]

I tend to overcomplicate things sometimes....

It'll work, but you may run into limitations as your tank matures

 

[salty_dog]

Thank you all for your input.

I decided to let the tank ride without a water change now 5 days since, testing alk at same time 10pm, and it's at 5 dkh now. Down from 8 after large water change last week. There is a lot of what I think is a green coralline. I'll add a picture after I clean up the tank for the photo. No hair algae grows on this stuff and it's in both my tanks on the rock, snails, and back wall.
I am mixing a batch of regular instant ocean and will check the alk to see if it's consistent.
Will go back to doing a 1L change every other day or daily if I have time for now.

Since I have a half bucket full of IO I plan to use that up and before a switch. Reef crystals sounds good given the price and it's available locally.
I hope a higher alk salt lets things stay even longer so less waterchanges. My current set up is a 5 gallon bucket with a return pump going 24/7. This keeps it warm too as I keep it on the porch away from the kids. Not super safe and I have caught them trying to scoop water and make their own "aquariums". . Maybe someday water mixing station in the garage.

 

[salty_dog]

My big purple bucket of IO is mixing at dkh of 9. Did a big water change and tank looks happier.
Here are some shots of what I wonder maybe a green coralline? It’s been there in both my tanks for a month or two. Note the purple on the rocks is the caribsea life rock paint.
Also found a spot of purple coraline on the overflow! . My montipora was a bunch of fragments I glued near each other now grew into one large piece.