Chalky Buildup on Heater?

NanaReefer · Oct 30, 2015

What is it and how can I prevent this from happening?

cloak · Oct 30, 2015

Check this out.

http://reefkeeping.com/issues/2005-07/rhf/index.php

HTH.

JOKER · Oct 30, 2015

When I dosed manually close to my heater I got some buildup.

Randy Holmes-Farley · Oct 30, 2015

Here's the relevant section from the article that cloak linked above:

Preventing Precipitates on Heaters and Pumps

While the calcium carbonate that precipitates onto heaters and pumps can be readily removed by soaking them in acid (undiluted vinegar or diluted muriatic acid/hydrochloric acid: 1 part acid added to 9 parts fresh water), it is often easier to prevent the buildup in the first place. The following actions can be taken if the aquarium has excessive precipitation of calcium carbonate:

Note: actions 1, 3, and 4 may also make it harder for calcifying organisms such as corals and coralline algae to calcify, so they may grow more slowly if a significant reduction is made in pH, calcium or alkalinity.

1. Reduce the overall pH. The lower the better for this purpose, but I wouldn't go below pH 7.8. Definitely target pH below pH 8.5, even at the end of the light cycle.

2. Add high pH additives (limewater/kalkwasser and high pH two-part calcium and alkalinity additive systems, especially) so that they mix quickly and do not enter pumps or pass over heaters before mixing in well. Add them at times of the day when low pH conditions exist (usually early morning). Reduce these types of additives, if necessary.

3. Reduce the alkalinity. The lower the better for this purpose, but I would not target levels below 2.5 meq/L (7 dKH). Definitely target alkalinity below 4 meq/L (11 dKH).

4. Reduce the calcium level. The lower the better for this purpose, but I would not target the calcium below 380ppm. Definitely target the calcium below 500 ppm.

5. Maintain an appropriate magnesium level of 1250 -1350 ppm. Higher levels (up to, say, 1500 ppm) will help reduce precipitation further, and some aquarists have resorted to this, but I do not know at what level magnesium becomes toxic.

6. If you use an iron-based phosphate binder, either situate it well upstream of pumps and heaters or discontinue its use. Chelated iron supplements (added to supply macroalgae with iron) are not as likely, in my opinion, to cause precipitation, but may still contribute to some degree.

7. Use pumps that do not get as hot internally (external heat is not the concern here). I do not, however, have specific advice on which pumps would be best in this regard. Plastic impellers, while wonderful from a chemical resistance standpoint, are poor heat conductors, so the heat that comes from pushing against the water is not as rapidly dissipated as it would be by impellers made from other materials.

8. Elevated phosphate and organics can reduce calcium carbonate precipitation. While I do not recommend intentionally raising these for this purpose, aquarists may find that if they reduce the levels of these materials, that precipitation may become worse.

NanaReefer · Oct 30, 2015

Ok making sense. I didn't have this issue until adding the reactor. The return of which is sitting pretty close to the heater. I'll move it.
I'm leaving my parameters be for now. They've been to well balanced [emoji106]

Thank you again Randy. Happy reefing! [emoji41]

Randy Holmes-Farley · Oct 31, 2015

You're welcome.

Happy Halloween!

NanaReefer · Nov 12, 2015

Update: Moved the return of my reactor, no more precipitation on heater. [emoji119]

Randy Holmes-Farley · Nov 12, 2015

That's good to hear.

Happy Reefing.

NanaReefer · Dec 2, 2015

Well the precipitation is back, again covering my heater. I'm pretty sure it's the SeaGel I'm running in the reactor that's causing the issue. Going to try moving the reactors return before taking it off line.

Randy Holmes-Farley · Dec 2, 2015

Most tanks (including mine) get calcium carbonate buildup on heaters. CaCO3 is less soluble at higher temps, and seawater is already supersaturated, so that is a common place to precipitate.

NanaReefer · Dec 2, 2015

I never had this problem before I started running the reactor. Is it the PhosGaurd that's causing the issue?
I've tested my PH at several different times of the day. At its highest 8.3, lowest 8.0.

Randy Holmes-Farley · Dec 3, 2015

I'm not aware of phosguard or aluminum causing this issue.

Things that do cause it include low magnesium, high alk and calcium and pH, maybe low organics and phosphate, and higher temperature. pH is a big driver. The difference between pH 8.0 and 8.3 is equivalent to a doubling in alkalinity or calcium for this purpose.

Randy Holmes-Farley · Dec 3, 2015

I'm not aware of phosguard or aluminum causing this issue.

Things that do cause it include low magnesium, high alk and calcium and pH, maybe low organics and phosphate, and higher temperature. pH is a big driver. The difference between pH 8.0 and 8.3 is equivalent to a doubling in alkalinity or calcium for this purpose.

NanaReefer · Dec 3, 2015

Randy would have any suggestions in my case for a fix?

Randy Holmes-Farley · Dec 3, 2015

NanaReefer said:
Randy would have any suggestions in my case for a fix?

To reduce the precipitate on the heater?

NanaReefer · Dec 3, 2015

Yes. Current numbers are ALK=8.4, Calc=440, Mag=1360, PH=8.2, Temp=79.2

Randy Holmes-Farley · Dec 3, 2015

I would just keep it upstream or far away from where you dose alkalinity. Other than that, just clean it once in a while, but mine get sheaths of deposits so thick that it breaks off in chunks.

NanaReefer · Dec 3, 2015

Randy Holmes-Farley said:
I would just keep it upstream or far away from where you dose alkalinity. Other than that, just clean it once in a while, but mine get sheaths of deposits so thick that it breaks off in chunks.

[emoji23] are you funny! Thanks Randy [emoji2]